https://github.com/mvxt/sudoku-validator
Solution for Interview Problem - Validate Sudoku Puzzle
https://github.com/mvxt/sudoku-validator
arrays dataductus hashset interview interview-questions sudoku-checker
Last synced: about 2 months ago
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Solution for Interview Problem - Validate Sudoku Puzzle
- Host: GitHub
- URL: https://github.com/mvxt/sudoku-validator
- Owner: mvxt
- License: mit
- Created: 2018-09-27T07:45:09.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2018-10-17T18:29:45.000Z (over 7 years ago)
- Last Synced: 2025-12-31T16:06:01.134Z (6 months ago)
- Topics: arrays, dataductus, hashset, interview, interview-questions, sudoku-checker
- Language: Java
- Homepage:
- Size: 13.7 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# Sudoku Validator
This is the repository for Data Ductus round 2 interview question solution, implemented in Java. The goal is to write a function which, given a 2D array of integers representing a Sudoku puzzle, validates the given solution.
## Background
Sudoku is a 9x9 grid puzzle. You are usually given an incomplete puzzle with only a few numbers, and based on logic, you are supposed to fill in the rest of the puzzle. See the [Wikipedia](https://en.wikipedia.org/wiki/Sudoku) article for more information.
The rules are as follows:
- All rows must contain numbers 1-9 uniquely
- All columns must contain numbers 1-9 uniquely
- All 3x3 squares at 0,0 / 0,3 / 0,6 / 3,0 / 3,3 / 3,6 / 6,0 / 6,3 / 6,6 must contain numbers 1-9 uniquely
## Setup
You must have minimum Java 7 installed.
1. Clone the repository and `cd` into it.
```
$ git clone https://github.com/mvxt/sudoku-validator && cd sudoku-validator
```
2. Build the project.
```
$ make
```
3. Run the project.
```
$ java SudokuValidator
```
## Overview of Solution(s)
One implementation could be to iterate through all rows, then all columns, then each of the squares to check for 1-9 uniqueness. If we assume for N to be the number of rows and columns, then this runtime would be O(n^2) complexity. This naive implementation can be seen on commit [e393241](https://github.com/mvxt/sudoku-validator/commit/e3932417992cc80cd390f880b4f3f0fae1bc7b5e).