https://github.com/amreshpro/pro150problems
https://github.com/amreshpro/pro150problems
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- Host: GitHub
- URL: https://github.com/amreshpro/pro150problems
- Owner: amreshpro
- Created: 2024-12-03T16:12:44.000Z (6 months ago)
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- Last Pushed: 2024-12-03T16:17:14.000Z (6 months ago)
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README
# 150 Pro Problems
## Level 1
1. **Determining Even/Odd Numbers**
**Difficulty**: Easy
**Topics**: Basic Programming
**Description**: Write a program to check whether a number is even or odd.
**Example**:
Input: `number = 4`
Output: `Even`
Explanation: Since 4 is divisible by 2, it is an even number.
2. **Checking for Prime Numbers**
**Difficulty**: Easy
**Topics**: Basic Programming, Number Theory
**Description**: Write a program to determine if a number is prime.
**Example**:
Input: `number = 7`
Output: `Prime`
Explanation: 7 has no divisors other than 1 and itself, so it is a prime number.
3. **Validating Leap Years**
**Difficulty**: Easy
**Topics**: Basic Programming, Date Handling
**Description**: Write a program to check if a given year is a leap year.
**Example**:
Input: `year = 2020`
Output: `Leap Year`
Explanation: 2020 is divisible by 4 but not by 100, or it is divisible by 400, so it is a leap year.
4. **Calculating Armstrong Numbers**
**Difficulty**: Easy
**Topics**: Basic Programming, Number Theory
**Description**: Write a program to check if a number is an Armstrong number.
**Example**:
Input: `number = 153`
Output: `Armstrong Number`
Explanation: 153 is an Armstrong number because 1^3 + 5^3 + 3^3 = 153.
5. **Generating the Fibonacci Series**
**Difficulty**: Easy
**Topics**: Basic Programming, Sequences
**Description**: Write a program to generate the Fibonacci series up to a given number.
**Example**:
Input: `limit = 10`
Output: `[0, 1, 1, 2, 3, 5, 8]`
Explanation: The Fibonacci series up to 10 is generated as [0, 1, 1, 2, 3, 5, 8].
6. **Identifying Palindromes**
**Difficulty**: Easy
**Topics**: Basic Programming, String Manipulation
**Description**: Write a program to check if a string or number is a palindrome.
**Example**:
Input: `string = "radar"`
Output: `Palindrome`
Explanation: "radar" reads the same backward as forward.
7. **Crafting Star Patterns**
**Difficulty**: Easy
**Topics**: Basic Programming, Patterns
**Description**: Write a program to create different star patterns (e.g., pyramid, diamond).
**Example**:
Input: `patternType = "pyramid", height = 5`
Output:
```
*
***
*****
*******
*********
```
Explanation: A pyramid pattern with a height of 5 is generated.
8. **Finding the Factorial of a Number**
**Difficulty**: Easy
**Topics**: Basic Programming, Mathematical Computations
**Description**: Write a program to compute the factorial of a given number.
**Example**:
Input: `number = 5`
Output: `120`
Explanation: 5! (factorial) is 5 × 4 × 3 × 2 × 1 = 120.
9. **Summing Digits of a Number**
**Difficulty**: Easy
**Topics**: Basic Programming, Mathematical Computations
**Description**: Write a program to calculate the sum of digits of a number.
**Example**:
Input: `number = 1234`
Output: `10`
Explanation: The sum of the digits 1 + 2 + 3 + 4 = 10.
10. **Finding the Greatest Common Divisor (GCD)**
**Difficulty**: Easy
**Topics**: Basic Programming, Number Theory
**Description**: Write a program to find the GCD of two numbers.
**Example**:
Input: `a = 48, b = 18`
Output: `6`
Explanation: The GCD of 48 and 18 is 6.
11. **Finding the Least Common Multiple (LCM)**
**Difficulty**: Easy
**Topics**: Basic Programming, Number Theory
**Description**: Write a program to find the LCM of two numbers.
**Example**:
Input: `a = 12, b = 15`
Output: `60`
Explanation: The LCM of 12 and 15 is 60.
12. **Counting Vowels and Consonants in a String**
**Difficulty**: Easy
**Topics**: Basic Programming, String Manipulation
**Description**: Write a program to count vowels and consonants in a given string.
**Example**:
Input: `string = "hello world"`
Output: `Vowels: 3, Consonants: 7`
Explanation: "hello world" contains 3 vowels (e, o, o) and 7 consonants (h, l, l, w, r, l, d).
13. **Reversing a String**
**Difficulty**: Easy
**Topics**: Basic Programming, String Manipulation
**Description**: Write a program to reverse a given string.
**Example**:
Input: `string = "programming"`
Output: `"gnimmargorp"`
Explanation: The reversed string of "programming" is "gnimmargorp".
14. **Finding the Largest and Smallest Numbers in an Array**
**Difficulty**: Easy
**Topics**: Basic Programming, Arrays
**Description**: Write a program to find the largest and smallest numbers in an array.
**Example**:
Input: `array = [4, 7, 1, 8, 5]`
Output: `Largest: 8, Smallest: 1`
Explanation: The largest number in the array is 8 and the smallest is 1.
15. **Sorting an Array**
**Difficulty**: Easy
**Topics**: Basic Programming, Sorting Algorithms
**Description**: Write a program to sort an array of numbers in ascending order.
**Example**:
Input: `array = [3, 1, 4, 1, 5, 9]`
Output: `[1, 1, 3, 4, 5, 9]`
Explanation: The array sorted in ascending order is [1, 1, 3, 4, 5, 9].
16. **Finding the Sum of Elements in an Array**
**Difficulty**: Easy
**Topics**: Basic Programming, Arrays
**Description**: Write a program to find the sum of elements in an array.
**Example**:
Input: `array = [1, 2, 3, 4, 5]`
Output: `15`
Explanation: The sum of the elements in the array is 15.
17. **Checking for Armstrong Numbers in a Range**
**Difficulty**: Easy
**Topics**: Basic Programming, Number Theory
**Description**: Write a program to find all Armstrong numbers within a given range.
**Example**:
Input: `range = [1, 500]`
Output: `[1, 153, 370, 371, 407]`
Explanation: Armstrong numbers between 1 and 500 are 1, 153, 370, 371, and 407.
18. **Generating Multiplication Tables**
**Difficulty**: Easy
**Topics**: Basic Programming, Mathematical Computations
**Description**: Write a program to generate multiplication tables for a given number.
**Example**:
Input: `number = 4`
Output:
```
4 x 1 = 4
4 x 2 = 8
4 x 3 = 12
4 x 4 = 16
4 x 5 = 20
```
Explanation: The multiplication table for 4 up to 5 is generated.
19. **Finding Prime Numbers in a Range**
**Difficulty**: Easy
**Topics**: Basic Programming, Number Theory
**Description**: Write a program to find all prime numbers within a given range.
**Example**:
Input: `range = [10, 30]`
Output: `[11, 13, 17, 19, 23, 29]`
Explanation: Prime numbers between 10 and 30 are 11, 13, 17, 19, 23, and 29.
20. **Checking for Perfect Numbers**
**Difficulty**: Easy
**Topics**: Basic Programming, Number Theory
**Description**: Write a program to determine if a number is a perfect number.
**Example**:
Input: `number = 28`
Output: `Perfect Number`
Explanation: 28 is a perfect number because its divisors (1, 2, 4, 7, 14) sum up to 28.
21. **Calculating the Sum of Even Numbers in a Range**
**Difficulty**: Easy
**Topics**: Basic Programming, Mathematical Computations
**Description**: Write a program to find the sum of all even numbers within a given range.
**Example**:
Input: `range = [1, 10]`
Output: `30`
Explanation: The sum of even numbers between 1 and 10 is 2 + 4 + 6 + 8 + 10 = 30.
22. **Calculating the Sum of Odd Numbers in a Range**
**Difficulty**: Easy
**Topics**: Basic Programming, Mathematical Computations
**Description**: Write a program to find the sum of all odd numbers within a given range.
**Example**:
Input: `range = [1, 10]`
Output: `25`
Explanation: The sum of odd numbers between 1 and 10 is 1 + 3 + 5 + 7 + 9 = 25.
23. **Finding the Fibonacci Number at a Specific Position**
**Difficulty**: Easy
**Topics**: Basic Programming, Sequences
**Description**: Write a program to find the Fibonacci number at a specific position.
**Example**:
Input: `position = 5`
Output: `5`
Explanation: The Fibonacci number at position 5 is 5 (sequence: 0, 1, 1, 2, 3, 5).
24. **Printing Prime Numbers Less Than a Given Number**
**Difficulty**: Easy
**Topics**: Basic Programming, Number Theory
**Description**: Write a program to print all prime numbers less than a given number.
**Example**:
Input: `number = 20`
Output: `2, 3, 5, 7, 11, 13, 17, 19`
Explanation: The prime numbers less than 20 are 2, 3, 5, 7, 11, 13, 17, and 19.
25. **Finding the Number of Digits in a Number**
**Difficulty**: Easy
**Topics**: Basic Programming, Mathematical Computations
**Description**: Write a program to count the number of digits in a given number.
**Example**:
Input: `number = 12345`
Output: `5`
Explanation: The number 12345 has 5 digits.
26. **Checking if a Number is a Narcissistic Number**
**Difficulty**: Easy
**Topics**: Basic Programming, Number Theory
**Description**: Write a program to check if a number is a narcissistic number (where the sum of its digits raised to the power of the number of digits equals the number itself).
**Example**:
Input: `number = 153`
Output: `Narcissistic Number`
Explanation: 153 is a narcissistic number because 1^3 + 5^3 + 3^3 = 153.
27. **Generating a Pattern of Numbers**
**Difficulty**: Easy
**Topics**: Basic Programming, Patterns
**Description**: Write a program to generate number patterns (e.g., sequential numbers in a matrix).
**Example**:
Input: `rows = 3`
Output:
```
1
2 3
4 5 6
```
Explanation: A number pattern with 3 rows is generated.
28. **Finding the Sum of the Digits of the Factorial of a Number**
**Difficulty**: Easy
**Topics**: Basic Programming, Mathematical Computations
**Description**: Write a program to find the sum of the digits of the factorial of a given number.
**Example**:
Input: `number = 4`
Output: `9`
Explanation: The factorial of 4 is 24, and the sum of the digits (2 + 4) is 6.
29. **Finding the Largest Palindrome in a String**
**Difficulty**: Easy
**Topics**: Basic Programming, String Manipulation
**Description**: Write a program to find the largest palindrome in a given string.
**Example**:
Input: `string = "babad"`
Output: `"bab"` or `"aba"`
Explanation: Both "bab" and "aba" are valid palindromes in the string.
30. **Finding Missing Numbers in a Sequence**
**Difficulty**: Easy
**Topics**: Basic Programming, Arrays
**Description**: Write a program to find missing numbers in a sequence from 1 to n.
**Example**:
Input: `sequence = [1, 2, 4, 5]`
Output: `[3]`
Explanation: The missing number in the sequence from 1 to 5 is 3.
31. **Generating a Pascal’s Triangle**
**Difficulty**: Medium
**Topics**: Arrays, Mathematical Computations
**Description**: Write a program to generate Pascal's Triangle up to a given number of rows.
**Example**:
Input: `rows = 4`
Output:
```
1
1 1
1 2 1
1 3 3 1
```
Explanation: Pascal's Triangle with 4 rows is generated.
32. **Finding the Median of an Array**
**Difficulty**: Medium
**Topics**: Arrays, Sorting
**Description**: Write a program to find the median of an array of numbers.
**Example**:
Input: `array = [3, 1, 2, 4, 5]`
Output: `3`
Explanation: The median of the sorted array [1, 2, 3, 4, 5] is 3.
33. **Calculating the Power of a Number**
**Difficulty**: Easy
**Topics**: Basic Programming, Mathematical Computations
**Description**: Write a program to calculate the power of a number.
**Example**:
Input: `base = 2`, `exponent = 3`
Output: `8`
Explanation: 2 raised to the power of 3 is 8.
34. **Checking for an Anagram**
**Difficulty**: Easy
**Topics**: String Manipulation
**Description**: Write a program to check if two strings are anagrams.
**Example**:
Input: `string1 = "listen"`, `string2 = "silent"`
Output: `True`
Explanation: "listen" and "silent" are anagrams of each other.
35. **Finding the Sum of Prime Numbers in a Range**
**Difficulty**: Medium
**Topics**: Number Theory, Mathematical Computations
**Description**: Write a program to calculate the sum of all prime numbers within a given range.
**Example**:
Input: `range = [1, 10]`
Output: `17`
Explanation: The sum of prime numbers between 1 and 10 is 2 + 3 + 5 + 7 = 17.
36. **Finding the N-th Triangular Number**
**Difficulty**: Easy
**Topics**: Basic Programming, Mathematical Computations
**Description**: Write a program to find the N-th triangular number.
**Example**:
Input: `N = 4`
Output: `10`
Explanation: The 4th triangular number is 10 (sum of the first 4 natural numbers).
37. **Checking for Perfect Squares**
**Difficulty**: Easy
**Topics**: Mathematical Computations
**Description**: Write a program to determine if a number is a perfect square.
**Example**:
Input: `number = 16`
Output: `True`
Explanation: 16 is a perfect square (4^2 = 16).
38. **Finding the Sum of Squares of Digits**
**Difficulty**: Easy
**Topics**: Basic Programming, Mathematical Computations
**Description**: Write a program to find the sum of the squares of the digits of a number.
**Example**:
Input: `number = 123`
Output: `14`
Explanation: The sum of the squares of digits is 1^2 + 2^2 + 3^2 = 14.
39. **Generating a Square Matrix of a Given Size**
**Difficulty**: Medium
**Topics**: Arrays, Matrix Operations
**Description**: Write a program to generate a square matrix of a given size and fill it with sequential numbers.
**Example**:
Input: `size = 3`
Output:
```
1 2 3
4 5 6
7 8 9
```
Explanation: A 3x3 matrix is generated with sequential numbers.
40. **Calculating the Sum of Digits of a Number Until Single Digit**
**Difficulty**: Medium
**Topics**: Mathematical Computations
**Description**: Write a program to keep summing the digits of a number until a single digit is obtained.
**Example**:
Input: `number = 9875`
Output: `2`
Explanation: The sum of digits is 9 + 8 + 7 + 5 = 29, and then 2 + 9 = 11, and finally 1 + 1 = 2.
41. **Finding the Count of Specific Digits in a Number**
**Difficulty**: Easy
**Topics**: Basic Programming, String Manipulation
**Description**: Write a program to count the occurrences of a specific digit in a number.
**Example**:
Input: `number = 122333`, `digit = 3`
Output: `3`
Explanation: The digit 3 occurs 3 times in the number 122333.
42. **Generating a Fibonacci Sequence Using Recursion**
**Difficulty**: Medium
**Topics**: Recursion, Sequences
**Description**: Write a recursive program to generate the Fibonacci sequence up to a given number.
**Example**:
Input: `number = 5`
Output: `0, 1, 1, 2, 3`
Explanation: The Fibonacci sequence up to 5 is generated.
43. **Finding All Divisors of a Number**
**Difficulty**: Easy
**Topics**: Basic Programming, Mathematical Computations
**Description**: Write a program to find all divisors of a given number.
**Example**:
Input: `number = 12`
Output: `1, 2, 3, 4, 6, 12`
Explanation: The divisors of 12 are 1, 2, 3, 4, 6, and 12.
44. **Finding the Average of Numbers in an Array**
**Difficulty**: Easy
**Topics**: Arrays, Mathematical Computations
**Description**: Write a program to calculate the average of numbers in an array.
**Example**:
Input: `array = [1, 2, 3, 4, 5]`
Output: `3`
Explanation: The average of the numbers is (1 + 2 + 3 + 4 + 5) / 5 = 3.
45. **Finding the Mode of Numbers in an Array**
**Difficulty**: Medium
**Topics**: Arrays, Statistical Analysis
**Description**: Write a program to find the mode (most frequent number) in an array.
**Example**:
Input: `array = [1, 2, 2, 3, 4, 4, 4]`
Output: `4`
Explanation: The most frequent number in the array is 4.
46. **Determining the Length of a String Without Using Built-In Functions**
**Difficulty**: Medium
**Topics**: String Manipulation
**Description**: Write a program to determine the length of a string without using built-in functions.
**Example**:
Input: `string = "hello"`
Output: `5`
Explanation: The length of the string "hello" is determined without using built-in functions.
47. **Generating a Number Pyramid**
**Difficulty**: Medium
**Topics**: Patterns, Basic Programming
**Description**: Write a program to generate a pyramid of numbers (e.g., 1, 12, 123, etc.).
**Example**:
Input: `rows = 4`
Output:
```
1
12
123
1234
```
Explanation: A number pyramid with 4 rows is generated.
48. **Finding the Sum of Prime Factors of a Number**
**Difficulty**: Medium
**Topics**: Number Theory, Mathematical Computations
**Description**: Write a program to find the sum of the prime factors of a given number.
**Example**:
Input: `number = 12`
Output: `5`
Explanation: The prime factors of 12 are 2 and 3, and their sum is 2 + 3 = 5.
49. **Finding the Second Largest Number in an Array**
**Difficulty**: Medium
**Topics**: Arrays, Sorting
**Description**: Write a program to find the second largest number in an array.
**Example**:
Input: `array = [10, 20, 4, 45, 99]`
Output: `45`
Explanation: The second largest number in the array is 45.
50. **Finding the Longest Substring Without Repeating Characters**
**Difficulty**: Medium
**Topics**: String Manipulation, Sliding Window
**Description**: Write a program to find the longest substring without repeating characters in a given string.
**Example**:
Input: `string = "abcabcbb"`
Output: `"abc"`
Explanation: The longest substring without repeating characters is "abc".
## Level 2
1. **Finding the Sum of Digits of a Number Until Zero**
**Difficulty**: Easy
**Topics**: Basic Programming, Mathematical Computations
**Description**: Write a program to repeatedly sum the digits of a number until the result is zero.
**Example**:
Input: `number = 123`
Output: `6`
Explanation: Sum of digits is 1 + 2 + 3 = 6; sum of digits of 6 is 6 (which is a single digit).
2. **Generating a Multiplication Table for a Range**
**Difficulty**: Easy
**Topics**: Arrays, Basic Programming
**Description**: Write a program to generate multiplication tables for numbers within a specified range.
**Example**:
Input: `start = 2`, `end = 4`
Output:
```
2 x 1 = 2 3 x 1 = 3 4 x 1 = 4
2 x 2 = 4 3 x 2 = 6 4 x 2 = 8
2 x 3 = 6 3 x 3 = 9 4 x 3 = 12
2 x 4 = 8 3 x 4 = 12 4 x 4 = 16
```
3. **Calculating the Sum of a Series (1 + 1/2 + 1/3 + ... + 1/n)**
**Difficulty**: Medium
**Topics**: Mathematical Computations
**Description**: Write a program to calculate the sum of the series 1 + 1/2 + 1/3 + ... + 1/n up to the nth term.
**Example**:
Input: `n = 4`
Output: `2.083333`
Explanation: Sum of the series is 1 + 1/2 + 1/3 + 1/4 ≈ 2.083333.
4. **Finding All Pairs of Elements in an Array that Add Up to a Given Sum**
**Difficulty**: Medium
**Topics**: Arrays, Hashing
**Description**: Write a program to find all pairs of elements in an array whose sum equals a specified target.
**Example**:
Input: `array = [1, 2, 3, 4, 5]`, `target = 5`
Output: `[(1, 4), (2, 3)]`
Explanation: Pairs that sum up to 5 are (1, 4) and (2, 3).
5. **Generating a Diamond Pattern of Stars**
**Difficulty**: Medium
**Topics**: Patterns, Basic Programming
**Description**: Write a program to create a diamond pattern with stars of a given size.
**Example**:
Input: `size = 5`
Output:
```
*
***
*****
***
*
```
6. **Counting the Number of Palindromic Substrings in a String**
**Difficulty**: Medium
**Topics**: String Manipulation
**Description**: Write a program to count how many palindromic substrings exist in a given string.
**Example**:
Input: `string = "aaa"`
Output: `6`
Explanation: Palindromic substrings are "a", "a", "a", "aa", "aa", "aaa".
7. **Generating a Matrix with Multiplication Table**
**Difficulty**: Easy
**Topics**: Arrays, Matrix Operations
**Description**: Write a program to generate a matrix where each element at position (i, j) is the product of i and j.
**Example**:
Input: `size = 3`
Output:
```
1 2 3
2 4 6
3 6 9
```
8. **Finding the GCD of Multiple Numbers**
**Difficulty**: Medium
**Topics**: Mathematical Computations
**Description**: Write a program to find the GCD (Greatest Common Divisor) of an array of numbers.
**Example**:
Input: `array = [12, 24, 36]`
Output: `12`
Explanation: The GCD of 12, 24, and 36 is 12.
9. **Finding the Sum of the First N Odd Numbers**
**Difficulty**: Easy
**Topics**: Mathematical Computations
**Description**: Write a program to calculate the sum of the first N odd numbers.
**Example**:
Input: `N = 5`
Output: `25`
Explanation: Sum of the first 5 odd numbers (1 + 3 + 5 + 7 + 9) is 25.
10. **Finding the Number of Perfect Numbers Up to a Given Limit**
**Difficulty**: Medium
**Topics**: Number Theory
**Description**: Write a program to find how many perfect numbers exist up to a given limit.
**Example**:
Input: `limit = 30`
Output: `1`
Explanation: There is only one perfect number (6) up to 30.
11. **Finding the Largest Prime Factor of a Number**
**Difficulty**: Medium
**Topics**: Number Theory
**Description**: Write a program to find the largest prime factor of a given number.
**Example**:
Input: `number = 28`
Output: `7`
Explanation: The prime factors of 28 are 2 and 7, with the largest being 7.
12. **Generating a Matrix of Fibonacci Numbers**
**Difficulty**: Medium
**Topics**: Arrays, Matrix Operations
**Description**: Write a program to generate a matrix where each element is a Fibonacci number.
**Example**:
Input: `size = 3`
Output:
```
1 1 2
3 5 8
13 21 34
```
13. **Finding the Sum of the First N Prime Numbers**
**Difficulty**: Medium
**Topics**: Prime Numbers, Mathematical Computations
**Description**: Write a program to calculate the sum of the first N prime numbers.
**Example**:
Input: `N = 4`
Output: `17`
Explanation: The sum of the first 4 prime numbers (2 + 3 + 5 + 7) is 17.
14. **Checking for a Balanced Bracket Sequence**
**Difficulty**: Medium
**Topics**: String Manipulation, Stack
**Description**: Write a program to check if a given string with brackets is balanced.
**Example**:
Input: `string = "{[()]}"`
Output: `True`
Explanation: The brackets are balanced.
15. **Finding the Sum of Numbers in a String**
**Difficulty**: Easy
**Topics**: String Manipulation
**Description**: Write a program to extract and sum all numbers present in a given string.
**Example**:
Input: `string = "The numbers are 12 and 34"`
Output: `46`
Explanation: The sum of numbers 12 and 34 is 46.
16. **Finding the Longest Consecutive Sequence in an Array**
**Difficulty**: Medium
**Topics**: Arrays, Hashing
**Description**: Write a program to find the longest sequence of consecutive numbers in an array.
**Example**:
Input: `array = [100, 4, 200, 1, 3, 2]`
Output: `4`
Explanation: The longest consecutive sequence is [1, 2, 3, 4].
17. **Generating a Matrix with a Spiral Pattern**
**Difficulty**: Medium
**Topics**: Arrays, Matrix Operations
**Description**: Write a program to generate a matrix filled with numbers in a spiral pattern.
**Example**:
Input: `size = 3`
Output:
```
1 2 3
8 9 4
7 6 5
```
18. **Finding All Subsets of a Set**
**Difficulty**: Medium
**Topics**: Combinatorics
**Description**: Write a program to generate all possible subsets of a given set of numbers.
**Example**:
Input: `set = [1, 2]`
Output: `[[], [1], [2], [1, 2]]`
Explanation: The subsets of [1, 2] are the empty set, [1], [2], and [1, 2].
19. **Checking for Perfect Squares in a Range**
**Difficulty**: Easy
**Topics**: Mathematical Comput
ations
**Description**: Write a program to check which numbers in a given range are perfect squares.
**Example**:
Input: `start = 1`, `end = 10`
Output: `[1, 4, 9]`
Explanation: Perfect squares between 1 and 10 are 1, 4, and 9.
20. **Finding the Sum of Diagonal Elements in a Matrix**
**Difficulty**: Easy
**Topics**: Matrix Operations
**Description**: Write a program to calculate the sum of the diagonal elements in a square matrix.
**Example**:
Input: `matrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]`
Output: `15`
Explanation: The sum of the diagonal elements (1 + 5 + 9) is 15.
21. **Finding the Second Smallest Number in an Array**
**Difficulty**: Easy
**Topics**: Arrays
**Description**: Write a program to find the second smallest number in an array.
**Example**:
Input: `array = [12, 13, 1, 10, 34, 1]`
Output: `10`
Explanation: The second smallest number in the array is 10.
22. **Generating Pascal’s Triangle Up to N Rows**
**Difficulty**: Medium
**Topics**: Combinatorics
**Description**: Write a program to generate Pascal’s Triangle up to N rows.
**Example**:
Input: `N = 3`
Output:
```
1
1 1
1 2 1
```
23. **Finding the Sum of Digits of the Product of Two Numbers**
**Difficulty**: Easy
**Topics**: Mathematical Computations
**Description**: Write a program to find the sum of the digits of the product of two given numbers.
**Example**:
Input: `number1 = 12`, `number2 = 34`
Output: `9`
Explanation: The product of 12 and 34 is 408, and the sum of its digits is 4 + 0 + 8 = 12.
24. **Checking for Palindromic Numbers in a Range**
**Difficulty**: Medium
**Topics**: Mathematical Computations
**Description**: Write a program to check for palindromic numbers within a given range.
**Example**:
Input: `start = 1`, `end = 100`
Output: `[1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44, 55, 66, 77, 88, 99]`
Explanation: Palindromic numbers between 1 and 100 are the numbers listed.
25. **Generating a Matrix with Alternating 0s and 1s**
**Difficulty**: Easy
**Topics**: Arrays, Matrix Operations
**Description**: Write a program to generate a matrix where the elements alternate between 0 and 1.
**Example**:
Input: `size = 3`
Output:
```
0 1 0
1 0 1
0 1 0
```
26. **Finding the Count of a Specific Word in a String**
**Difficulty**: Easy
**Topics**: String Manipulation
**Description**: Write a program to count how many times a specific word appears in a given string.
**Example**:
Input: `string = "hello world hello"`
Output: `2`
Explanation: The word "hello" appears 2 times in the string.
27. **Finding the Largest Sum of a Subarray**
**Difficulty**: Medium
**Topics**: Arrays, Dynamic Programming
**Description**: Write a program to find the largest sum of any contiguous subarray.
**Example**:
Input: `array = [-2, 1, -3, 4, -1, 2, 1, -5, 4]`
Output: `6`
Explanation: The largest sum is 6, from the subarray `[4, -1, 2, 1]`.
28. **Generating a Right-Angle Triangle Pattern of Numbers**
**Difficulty**: Easy
**Topics**: Patterns
**Description**: Write a program to create a right-angle triangle pattern with numbers.
**Example**:
Input: `height = 4`
Output:
```
1
12
123
1234
```
29. **Finding All Divisors of the Product of Two Numbers**
**Difficulty**: Medium
**Topics**: Number Theory
**Description**: Write a program to find all divisors of the product of two given numbers.
**Example**:
Input: `number1 = 6`, `number2 = 10`
Output: `[1, 2, 3, 5, 6, 10, 15, 30]`
Explanation: The product of 6 and 10 is 60, and its divisors are listed.
30. **Finding the Longest Sequence of Consecutive 1s in a Binary Array**
**Difficulty**: Medium
**Topics**: Arrays, Binary Operations
**Description**: Write a program to find the longest sequence of consecutive 1s in a binary array.
**Example**:
Input: `array = [1, 1, 0, 1, 1, 1]`
Output: `3`
Explanation: The longest sequence of 1s is `[1, 1, 1]` with length 3.
31. **Calculating the Sum of the First N Fibonacci Numbers**
**Difficulty**: Medium
**Topics**: Fibonacci Sequence, Mathematical Computations
**Description**: Write a program to calculate the sum of the first N Fibonacci numbers.
**Example**:
Input: `N = 5`
Output: `12`
Explanation: The first 5 Fibonacci numbers are 1, 1, 2, 3, 5, and their sum is 12.
32. **Checking for a Repeated Substring in a String**
**Difficulty**: Medium
**Topics**: String Manipulation
**Description**: Write a program to check if a substring is repeated within a given string.
**Example**:
Input: `string = "abab"`
Output: `True`
Explanation: The substring "ab" is repeated.
33. **Finding the Median of a List of Numbers**
**Difficulty**: Medium
**Topics**: Sorting, Mathematical Computations
**Description**: Write a program to find the median value of a list of numbers.
**Example**:
Input: `list = [3, 1, 4, 1, 5]`
Output: `3`
Explanation: After sorting the list to [1, 1, 3, 4, 5], the median is 3.
34. **Finding the Number of Words in a String**
**Difficulty**: Easy
**Topics**: String Manipulation
**Description**: Write a program to count the number of words in a given string.
**Example**:
Input: `string = "Hello world"`
Output: `2`
Explanation: There are 2 words in the string.
35. **Generating a Matrix with a Diagonal Pattern**
**Difficulty**: Medium
**Topics**: Matrix Operations
**Description**: Write a program to create a matrix where elements form diagonal lines of a given pattern.
**Example**:
Input: `size = 4`
Output:
```
1 0 0 0
1 1 0 0
1 1 1 0
1 1 1 1
```
36. **Finding the Sum of the First N Even Numbers**
**Difficulty**: Easy
**Topics**: Mathematical Computations
**Description**: Write a program to calculate the sum of the first N even numbers.
**Example**:
Input: `N = 4`
Output: `20`
Explanation: The first 4 even numbers are 2, 4, 6, 8, and their sum is 20.
37. **Finding the Count of Digits Greater Than a Specific Value**
**Difficulty**: Easy
**Topics**: Mathematical Computations
**Description**: Write a program to count how many digits in a number are greater than a specific value.
**Example**:
Input: `number = 54321`, `value = 3`
Output: `2`
Explanation: The digits
greater than 3 in 54321 are 5, 4, and 4, so the count is 2.
38. **Generating a Pattern of Prime Numbers**
**Difficulty**: Medium
**Topics**: Prime Numbers, Patterns
**Description**: Write a program to generate a pattern where each row contains the first few prime numbers.
**Example**:
Input: `rows = 3`
Output:
```
2
2 3
2 3 5
```
39. **Finding the Common Elements in Two Arrays**
**Difficulty**: Medium
**Topics**: Arrays
**Description**: Write a program to find common elements between two arrays.
**Example**:
Input: `array1 = [1, 2, 3, 4]`, `array2 = [3, 4, 5, 6]`
Output: `[3, 4]`
Explanation: The common elements between the two arrays are 3 and 4.
40. **Finding the Sum of the Squares of All Even Numbers Up to N**
**Difficulty**: Medium
**Topics**: Mathematical Computations
**Description**: Write a program to calculate the sum of squares of all even numbers up to a given N.
**Example**:
Input: `N = 4`
Output: `20`
Explanation: The even numbers up to 4 are 2 and 4, and their squares are 4 and 16. The sum is 20.
41. **Generating a Pattern of Increasing Numbers**
**Difficulty**: Easy
**Topics**: Patterns
**Description**: Write a program to create a pattern where numbers increase with each row.
**Example**:
Input: `rows = 3`
Output:
```
1
12
123
```
42. **Finding the Largest Element in Each Row of a Matrix**
**Difficulty**: Easy
**Topics**: Matrix Operations
**Description**: Write a program to find the largest element in each row of a matrix.
**Example**:
Input: `matrix = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]`
Output: `[3, 6, 9]`
Explanation: The largest elements in each row are 3, 6, and 9.
43. **Checking for Anagram Pairs in a List of Strings**
**Difficulty**: Medium
**Topics**: String Manipulation
**Description**: Write a program to find pairs of strings in a list that are anagrams of each other.
**Example**:
Input: `strings = ["listen", "silent", "hello", "world"]`
Output: `[("listen", "silent")]`
Explanation: "listen" and "silent" are anagrams.
44. **Finding the Frequency of Each Character in a String**
**Difficulty**: Easy
**Topics**: String Manipulation
**Description**: Write a program to count the frequency of each character in a given string.
**Example**:
Input: `string = "hello"`
Output: `{'h': 1, 'e': 1, 'l': 2, 'o': 1}`
Explanation: The frequency of each character in the string "hello" is shown.
45. **Generating a Matrix with Random Numbers**
**Difficulty**: Easy
**Topics**: Random Number Generation, Matrix Operations
**Description**: Write a program to generate a matrix filled with random numbers.
**Example**:
Input: `rows = 2`, `columns = 3`
Output:
```
3 8 1
7 4 6
```
46. **Finding the Length of the Longest Word in a String**
**Difficulty**: Easy
**Topics**: String Manipulation
**Description**: Write a program to find the length of the longest word in a given string.
**Example**:
Input: `string = "Find the longest word"`
Output: `8`
Explanation: The longest word is "longest" with length 8.
47. **Finding All Triplets in an Array That Sum to Zero**
**Difficulty**: Medium
**Topics**: Arrays, Sorting
**Description**: Write a program to find all unique triplets in an array that sum to zero.
**Example**:
Input: `array = [-1, 0, 1, 2, -1, -4]`
Output: `[[-1, -1, 2], [-1, 0, 1]]`
Explanation: The unique triplets that sum to zero are listed.
48. **Generating a Square Matrix with Random Values**
**Difficulty**: Easy
**Topics**: Random Number Generation, Matrix Operations
**Description**: Write a program to generate a square matrix where each element is a random value.
**Example**:
Input: `size = 3`
Output:
```
7 3 5
2 6 9
1 8 4
```
49. **Finding the Difference Between the Sum of Even and Odd Numbers in an Array**
**Difficulty**: Easy
**Topics**: Arrays, Mathematical Computations
**Description**: Write a program to calculate the difference between the sum of even and odd numbers in an array.
**Example**:
Input: `array = [1, 2, 3, 4, 5, 6]`
Output: `4`
Explanation: The sum of even numbers is 12, and the sum of odd numbers is 8. The difference is 4.
50. **Generating a Triangle Pattern of Stars with a Given Height**
**Difficulty**: Easy
**Topics**: Patterns
**Description**: Write a program to create a triangle pattern of stars with a specified height.
**Example**:
Input: `height = 4`
Output:
```
*
**
***
****
```
## Level 3
### **Problem 1: Print a Right-Angle Triangle of Stars**
**Difficulty:** Easy
**Topics:** Pattern Printing
**Hint:** Print a right-angle triangle pattern of stars (`*`). Each row should contain an increasing number of stars, starting from 1 star in the first row.
**Example 1:**
**Input:** `n = 4`
**Output:**
```
*
**
***
****
```
---
### **Problem 2: Print a Square of Stars**
**Difficulty:** Easy
**Topics:** Pattern Printing
**Hint:** Print a square pattern of stars (`*`). Each row and column should have the same number of stars.
**Example 1:**
**Input:** `n = 5`
**Output:**
```
*****
*****
*****
*****
*****
```
---
### **Problem 3: Print a Pyramid Pattern**
**Difficulty:** Easy
**Topics:** Pattern Printing
**Hint:** Print a pyramid pattern with stars (`*`). The pyramid should have a single peak and each row should have an increasing number of stars, centered horizontally.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
*
***
*****
```
---
### **Problem 4: Print a Diamond Pattern**
**Difficulty:** Easy
**Topics:** Pattern Printing
**Hint:** Print a diamond pattern with stars (`*`). The pattern should include a single peak in the middle with symmetric rows above and below it.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
*
***
*****
***
*
```
---
### **Problem 5: Print a Hollow Square of Stars**
**Difficulty:** Easy
**Topics:** Pattern Printing
**Hint:** Print a hollow square pattern with stars (`*`). The border of the square should be filled with stars while the inner part should be empty.
**Example 1:**
**Input:** `n = 5`
**Output:**
```
*****
* *
* *
* *
*****
```
### **Problem 6: Print a Number Triangle**
**Difficulty:** Easy
**Topics:** Pattern Printing
**Hint:** Print a right-angle triangle pattern with numbers. Each row should contain an increasing sequence of numbers starting from 1.
**Example 1:**
**Input:** `n = 4`
**Output:**
```
1
12
123
1234
```
---
### **Problem 7: Print an Inverted Triangle Pattern**
**Difficulty:** Easy
**Topics:** Pattern Printing
**Hint:** Print an inverted triangle pattern with stars (`*`). Each row should contain decreasing numbers of stars from the top row.
**Example 1:**
**Input:** `n = 5`
**Output:**
```
*****
****
***
**
*
```
---
### **Problem 8: Print a Diamond Pattern with Numbers**
**Difficulty:** Easy
**Topics:** Pattern Printing
**Hint:** Print a diamond pattern with numbers. The pattern should have a peak in the middle with symmetric rows above and below it.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
1
121
12321
121
1
```
---
### **Problem 9: Print a Right-Angle Triangle of Numbers**
**Difficulty:** Easy
**Topics:** Pattern Printing
**Hint:** Print a right-angle triangle pattern with increasing numbers. Each row should contain a continuous sequence of increasing numbers.
**Example 1:**
**Input:** `n = 4`
**Output:**
```
1
23
456
78910
```
---
### **Problem 10: Print a Pyramid Pattern with Numbers**
**Difficulty:** Easy
**Topics:** Pattern Printing
**Hint:** Print a pyramid pattern with increasing numbers. Each row should have an increasing sequence of numbers, centered horizontally.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
1
232
34543
```
---
### **Problem 11: Print a Pattern of Alternating 0s and 1s**
**Difficulty:** Medium
**Topics:** Matrix Pattern
**Hint:** Print a matrix where elements alternate between `0` and `1`. The pattern should alternate both row-wise and column-wise.
**Example 1:**
**Input:** `n = 4`
**Output:**
```
0101
1010
0101
1010
```
---
### **Problem 12: Print a Pascal’s Triangle**
**Difficulty:** Medium
**Topics:** Matrix Pattern
**Hint:** Print Pascal’s Triangle up to `N` rows. Each row should be constructed based on the sum of the elements directly above it in the previous row.
**Example 1:**
**Input:** `n = 4`
**Output:**
```
1
1 1
1 2 1
1 3 3 1
```
---
### **Problem 13: Print a Pattern of Consecutive Numbers**
**Difficulty:** Medium
**Topics:** Matrix Pattern
**Hint:** Print a matrix of consecutive numbers starting from 1, filling rows sequentially.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
1 2 3
4 5 6
7 8 9
```
---
### **Problem 14: Print a Star Pattern with Increasing Width**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a pattern where each row has an increasing width of stars.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
*
***
*****
```
---
### **Problem 15: Print a Right-Angle Triangle Pattern with Characters**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a right-angle triangle pattern using characters. Each row should contain the same character repeated according to the row number.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
A
BB
CCC
```
---
### **Problem 16: Print a Checkerboard Pattern**
**Difficulty:** Medium
**Topics:** Matrix Pattern
**Hint:** Print a checkerboard pattern with two different characters alternating.
**Example 1:**
**Input:** `n = 4`
**Output:**
```
XOXOXO
OXOXOX
XOXOXO
OXOXOX
```
---
### **Problem 17: Print a Pyramid Pattern of Increasing Stars**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a pyramid pattern where each row increases in the number of stars.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
*
***
*****
```
---
### **Problem 18: Print a Border Pattern with Numbers**
**Difficulty:** Medium
**Topics:** Matrix Pattern
**Hint:** Print a border pattern using numbers. The border should be filled with numbers, and the inner part should be empty.
**Example 1:**
**Input:** `n = 4`
**Output:**
```
1234
1 1
1 1
1234
```
---
### **Problem 19: Print an Inverted Pyramid Pattern with Characters**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print an inverted pyramid pattern using characters. Each row should have decreasing characters from the top row.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
CCC
BB
A
```
---
### **Problem 20: Print a Cross Pattern with Stars**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a cross pattern using stars. The cross should be centered within a matrix.
**Example 1:**
**Input:** `n = 5`
**Output:**
```
***
*
*
*
***
```
---
### **Problem 21: Print a Spiral Matrix**
**Difficulty:** Hard
**Topics:** Matrix Pattern
**Hint:** Print a matrix filled with numbers in a spiral pattern. The numbers should start from 1 and increment as you move around the spiral.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
1 2 3
8 9 4
7 6 5
```
---
### **Problem 22: Print a Diamond Pattern with Increasing Width**
**Difficulty:** Hard
**Topics:** Pattern Printing
**Hint:** Print a diamond pattern where each line has increasing width of stars.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
*
***
*****
***
*
```
---
### **Problem 23: Print a Diamond Pattern with Numbers Increasing**
**Difficulty:** Hard
**Topics:** Pattern Printing
**Hint:** Print a diamond pattern where numbers increase. Each row should show a symmetrical pattern with numbers increasing towards the center.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
1
121
12321
121
1
```
---
### **Problem 24: Print a Pattern of Increasing and Decreasing Stars**
**Difficulty:** Hard
**Topics:** Pattern Printing
**Hint:** Print a pattern where stars increase to a midpoint and then decrease.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
*
***
*****
***
*
```
---
### **Problem 25: Print a Matrix with Zigzag Pattern**
**Difficulty:** Hard
**Topics:** Matrix Pattern
**Hint:** Print a matrix with a zigzag pattern of numbers. The numbers should alternate direction row-wise.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
1 2 3 4
8 7 6 5
9 10 11 12
```
---
### **Problem 26: Print a Pattern of Alternating Characters in Rows**
**Difficulty:** Hard
**Topics:** Pattern Printing
**Hint:** Print a pattern where rows alternate between two characters.
**Example 1:**
**Input:** `n = 4`
**Output:**
```
ABAB
BABA
ABAB
BABA
```
---
### **Problem 27: Print a Number Pyramid Pattern with Characters**
**Difficulty:** Hard
**Topics:** Pattern Printing
**Hint:** Print a pyramid pattern using increasing characters, where each row increases in width and character range.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
A
BCD
EFGHI
```
---
### **Problem 28: Print a Pattern with Diagonal Lines**
**Difficulty:** Hard
**Topics:** Pattern Printing
**Hint:** Print a pattern with diagonal lines using characters. Each diagonal line should be aligned properly.
**Example 1:**
**Input:** `n = 4`
**Output:**
```
A
B B
C C
D D
```
---
### **Problem 29: Print a Matrix with Diamond Pattern of Numbers**
**Difficulty:** Hard
**Topics:** Matrix Pattern
**Hint:** Print a matrix where elements follow a diamond pattern with numbers.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
1
121
12321
121
1
```
---
### **Problem 30: Print a Cross Pattern of Stars with Diagonals**
**Difficulty:** Hard
**Topics:** Pattern Printing
**Hint:** Print a cross pattern using stars with intersecting diagonals.
**Example 1:**
**Input:** `n = 5`
**Output:**
```
* * * * *
* * * *
* * *
* *
*
* *
* * *
* * * *
* * * * *
```
### **Problem 31: Print a Triangular Matrix with Numbers**
**Difficulty:** Easy
**Topics:** Pattern Printing
**Hint:** Print a triangular matrix where each row contains increasing numbers. Each subsequent row should start from the next number.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
1
2 3
4 5 6
```
---
### **Problem 32: Print a Star Pattern with Increasing and Decreasing Width**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a pattern with stars that increase to a midpoint and then decrease. The stars should be centered horizontally.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
*
***
*****
***
*
```
---
### **Problem 33: Print a Pattern of Nested Squares**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a pattern with nested squares using stars. The outermost square should be filled with stars, and each subsequent square should be smaller and centered inside the previous one.
**Example 1:**
**Input:** `n = 5`
**Output:**
```
*****
* *
* *
* *
*****
```
---
### **Problem 34: Print a Pattern with Increasing Characters in Columns**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a pattern where each column contains increasing characters from `A`.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
A
B C
D E F
```
---
### **Problem 35: Print a Matrix with Spiral Diagonals**
**Difficulty:** Hard
**Topics:** Matrix Pattern
**Hint:** Print a matrix with numbers arranged in diagonal spirals. The numbers should fill the matrix in a diagonal spiral fashion.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
1 2 3
4 5 6
7 8 9
```
---
### **Problem 36: Print a Checkerboard Pattern with Increasing Size**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a checkerboard pattern where the size of each square increases as you move along the matrix.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
XOX
OXO
XOX
```
---
### **Problem 37: Print a Cross Pattern with Increasing Size**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a cross pattern where the size of the cross increases with each row. The pattern should be centered.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
*
***
*****
***
*
```
---
### **Problem 38: Print a Pattern of Alternating Triangles**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a pattern with alternating triangles of stars. The triangles should alternate direction.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
*
***
*****
***
*
```
---
### **Problem 39: Print a Matrix with Diamond Pattern of Numbers**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a matrix where numbers form a diamond pattern. The numbers should increase and decrease symmetrically around the center.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
1
121
12321
121
1
```
---
### **Problem 40: Print a Star Pattern with Increasing Width and Centered**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a pattern where the width of stars increases, and the stars are centered horizontally.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
*
***
*****
```
---
### **Problem 41: Print a Pattern with Spiral and Zigzag**
**Difficulty:** Hard
**Topics:** Matrix Pattern
**Hint:** Print a matrix with both spiral and zigzag patterns. The matrix should first fill in a spiral pattern and then in a zigzag fashion.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
1 2 3
6 5 4
7 8 9
```
---
### **Problem 42: Print a Pattern of Alternating Characters in Matrix**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a matrix where characters alternate in each cell to form a pattern.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
ABAB
BABA
ABAB
```
---
### **Problem 43: Print a Pattern with Nested Triangles**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a pattern with nested triangles of stars. Each triangle should be centered and decrease in size.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
*
***
*****
***
*
```
---
### **Problem 44: Print a Matrix with Increasing Rows and Columns**
**Difficulty:** Easy
**Topics:** Matrix Pattern
**Hint:** Print a matrix where each row and column contains increasing numbers.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
1 2 3
4 5 6
7 8 9
```
---
### **Problem 45: Print a Pattern with Rows of Increasing Characters**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a pattern where each row contains an increasing sequence of characters.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
A
BC
DEF
```
---
### **Problem 46: Print a Star Pattern with Diamond Shape and Numbers**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a pattern with a diamond shape of stars, with numbers inside the diamond.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
1
121
12321
121
1
```
---
### **Problem 47: Print a Matrix with Cross Pattern of Numbers**
**Difficulty:** Hard
**Topics:** Matrix Pattern
**Hint:** Print a matrix where the center forms a cross pattern with numbers.
**Example 1:**
**Input:** `n = 5`
**Output:**
```
12321
01210
01210
01210
12321
```
---
### **Problem 48: Print a Pattern with Concentric Squares**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a pattern with concentric squares using stars. The outer square should be larger and each subsequent square should be centered inside.
**Example 1:**
**Input:** `n = 5`
**Output:**
```
*****
* *
* *
* *
*****
```
---
### **Problem 49: Print a Pattern of Alternating Rows and Columns of Numbers**
**Difficulty:** Easy
**Topics:** Pattern Printing
**Hint:** Print a pattern with alternating rows and columns of numbers, where each row and column increases sequentially.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
123
456
789
```
---
### **Problem 50: Print a Matrix with Zigzag Pattern of Stars**
**Difficulty:** Medium
**Topics:** Pattern Printing
**Hint:** Print a matrix where stars form a zigzag pattern, alternating rows in their positioning.
**Example 1:**
**Input:** `n = 3`
**Output:**
```
* * *
* *
* * *
```