https://github.com/rurangiza/dojo
Learning data structures and algorithms
https://github.com/rurangiza/dojo
algorithms
data-structures
Last synced: over 1 year ago
JSON representation
Learning data structures and algorithms
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Host: GitHub
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URL: https://github.com/rurangiza/dojo
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Owner: rurangiza
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Created: 2022-04-22T19:54:42.000Z
(about 4 years ago)
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Default Branch: main
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Last Pushed: 2024-06-17T10:23:07.000Z
(about 2 years ago)
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Last Synced: 2024-06-17T11:49:10.900Z
(about 2 years ago)
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Topics: algorithms, data-structures
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Language: Jupyter Notebook
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Homepage:
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Size: 24.7 MB
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Stars: 0
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Watchers: 1
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Forks: 0
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Open Issues: 0
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Metadata Files:
Awesome Lists containing this project
# Welcome to the Dojo
## Data Structures & Algorithms
- [x] [Introduction to Data Structures](https://www.youtube.com/watch?v=X8h4dq9Hzq8)
- [x] [Introduction to Algorithms](https://www.youtube.com/live/4oqjcKenCH8?si=58ALyCO1klKIUVnm)
- [x] [What is a brute-force method](https://www.youtube.com/watch?v=kdTpUjd71G8)?
- [x] [Big-O Notation](https://youtu.be/BgLTDT03QtU?si=wU584KDbMbWFgak3)
> [!Important]
> For each data structure, algorithm and technique, do the following:
> learn the theory and concepts, then implement it in code and finally solve **5 easy** problems.
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|-|:-|:-:|:-:|
||**Data Structures**: way of organizing data for easier processing|**Theory & Implementation**|**Exercices**|
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|[Dynamic Arrays](https://en.wikipedia.org/wiki/Dynamic_array): order is important, fast read, fast back insert|[C](./src/theory/data_structures/vector.c) - [Python](./src/theory/data_structures/vector.py)|[Leetcode](https://leetcode.com/tag/array/)|
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|[Linked-List](https://en.wikipedia.org/wiki/Linked_list): order not important, sequence matters, fast front/mid insert|[C](./src/theory/data_structures/singly-linked-list.c) - [Python](./src/theory/data_structures/singly-linked-list.py)|[Leetcode](https://leetcode.com/tag/linked-list/)|
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|[Stack](https://en.wikipedia.org/wiki/Stack_(abstract_data_type)): frequent insert and remove at end = LIFO|[Python](./src/theory/data_structures/stack.ipynb)|[Leetcode](https://leetcode.com/tag/stack/)|
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|[Queues](https://en.wikipedia.org/wiki/Queue_(abstract_data_type)): frequent insert at end and remove from front = FIFO|[Python](./src/theory/data_structures/deque.ipynb)|[Leetcode](https://leetcode.com/tag/queue/)|
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|[Hash Tables](https://en.wikipedia.org/wiki/Hash_table): order not important, no duplicates, fast read/write/search|[Notes](./src/theory/data_structures/hashmap.ipynb)|[Leetcode](https://leetcode.com/tag/hash-table/)|
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|[Sets](https://en.wikipedia.org/wiki/Set_(abstract_data_type)): order not important, no duplicates, fast read/write/search, great to compare groups|||
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||**Algorithms**: step by step instructions for completing a task|**Theory & Implementation**|**Exercices**|
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|[Selection Sort](https://en.wikipedia.org/wiki/Selection_sort), [Bubble Sort](https://en.wikipedia.org/wiki/Bubble_sort), [Insertion Sort](https://www.youtube.com/watch?v=JU767SDMDvA) O(n^2)|[Notes](./src/theory/algorithms/sorting-quadratic.ipynb)|[Leetcode](https://leetcode.com/tag/heap-priority-queue/)|
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|[Merge Sort](https://www.youtube.com/watch?v=4VqmGXwpLqc), [Quick Sort](https://youtu.be/Hoixgm4-P4M?si=OUJ7I-78ubkbnJtp) O(nlogn)|[Notes](./src/theory/algorithms/sorting-nlogn.ipynb)|[Leetcode](https://leetcode.com/tag/sorting/)|
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|[Counting Sort](https://en.wikipedia.org/wiki/Counting_sort) [[2](https://www.youtube.com/watch?v=ZcUdXuzOzeU)] O(n) for limited range!|[Notes](./src/theory/algorithms/counting-sort.ipynb)|[Leetcode](https://leetcode.com/tag/counting-sort/)|
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|[Bucket Sort](https://en.wikipedia.org/wiki/Bucket_sort) [[2](https://www.youtube.com/watch?v=rNdTWHQMvOk)] ||[Leetcode](https://leetcode.com/tag/bucket-sort/)|
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|[Binary Search](https://youtu.be/fDKIpRe8GW4?si=WGFySWh7-3bU_iPX)|[Python](./src/theory/algorithms/binary-search.ipynb)|[Leetcode](https://leetcode.com/tag/binary-search/)|
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||**Techniques**: common ways of approaching common problems|**Theory & Implementation**|**Exercices**|
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|[Two Pointers](https://www.youtube.com/watch?v=-gjxg6Pln50)||[Leetcode](https://leetcode.com/tag/two-pointers/)|
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|[Prefix Sum](https://www.youtube.com/watch?v=7pJo_rM0z_s)||[Leetcode](https://leetcode.com/tag/prefix-sum/)|
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|[Sliding Window](https://www.youtube.com/watch?v=p-ss2JNynmw)||[Leetcode](https://leetcode.com/tag/sliding-window/)|
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||**Concepts**|**Theory & Concepts**|**Exercices**|
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|[Recursion](https://youtube.com/playlist?list=PLgUwDviBIf0rGlzIn_7rsaR2FQ5e6ZOL9&si=nf1SDr2ndMU5ENWB): function calling itself, required for trees, backtracking and dynamic programming||[Exercices](https://leetcode.com/tag/recursion/)|
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|[Bit Manipulation](https://youtu.be/NLKQEOgBAnw?si=oVl3SgLRvITKuN7x): fast operates without extra space required||[Exercices](https://leetcode.com/tag/bit-manipulation/)|
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|[Regular Expressions](https://youtu.be/NLKQEOgBAnw?si=oVl3SgLRvITKuN7x) / [2](https://realpython.com/regex-python/): quick match of complex patterns||[Exercices](https://www.hackerrank.com/domains/regex)|
[Neetcode's Roadmap](https://neetcode.io/roadmap)
## Codeforces
[](https://codeforces/profile/arurangi)
#### Topics per rating
|||||||
|-|-|:-:|:-|:-:|:-:|
||Title |Rating|Topics|Notes|Exercices|
|
|Newbie|0 - 1199|- Modular Arithmetic
- Basic knowledge of primes, multiples, divisors
- Euclidean algorithm
- Sieve of eatosthenes
- Binary modular eponentiation
- Combinatorics||Exercices|
|
|Pupil|1200 - 1399||||
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|Specialist|1400 - 1599||||
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|Expert|>= 1600||||
## Reminders in Python
#### Converting list to dictionnary counter
```python
from collections import Counter
array = [1, 2, 3, 4, 2, 2, 1, 4]
count = Counter(arr)
# Counter({2: 3, 1: 2, 4: 2, 3: 1})
```
#### Declaring 2D array filled with zeros
```python
mat = [[0] * m for _ in range(n)]
```
#### Sorting tuples by key
```python
data.sort(key=lambda x: x[0])
```
#### Walrus operator
```python
import time
def do_something() -> int:
sleep(1)
return 42
# slow
if do_something() == 42:
return do_something()
# much better
x = do_something()
if x == 42:
return x
# more concise, better? maybe
if (x := do_something()) == 42:
return x
```
[⇪ **Back up**](#dojo)