Importance of Sudoku Game Solver in C++

Implementing a Sudoku game solver in C++ using DSA not only helps in understanding the core concepts of programming but also in applying these concepts in creating a functional, interactive game.

Project Requirements

For this project you need a development environment with a recommended IDE that supports C++ development and debugging tools for a seamless coding experience.

• C++ Compiler (e.g., visual studio community)
• An Integrated Development Environment (IDE) like Visual Studio Code or Code::Blocks
• Standard Template Library (STL) for C++

NOTE

Download the project files from the GitHub repository via the provided link. You can clone the repository and utilize it on your local machine.

Download the Zip file directly by clicking on the download button below.

Definition and Importance of DSA

Data Structures are ways to organize and store data in a computer so that it can be accessed and modified efficiently. Algorithms are step-by-step procedures for performing calculations, data processing, and automated reasoning tasks.

Code Explanation

Breaking down the C++ project of sudoku game of DSA, explaining the purpose of each function and how it contributes to the overall functionality of the game.

Game Class Implementation

The main function’s role in initializing the game, setting the difficulty level, and starting the game loop. Detailed explanation of the Game class, including methods for generating the Sudoku puzzle, checking if a move is valid, and solving the puzzle.

Game Structure

Explaining the game’s architecture, including the main components such as the game board, the game logic, and the user interface. The Sudoku board is a 9×9 grid. This section will cover how to represent the board in C++ using arrays or matrices and how to initialize it with a valid puzzle.

#include "Game.h"

int main() {
    int difficultyLevel;
    do {
        cout << "\nEnter difficulty level :\n1. 40 for easy.\n2. 30 for medium\n3. 20 for hard\n ";
        cin >> difficultyLevel;

        if (difficultyLevel == 20 || difficultyLevel == 30 || difficultyLevel == 40) {
            break;
        }
        else
            cout << "Invalid Input! . Enter again: \n";
    } while (true);

    Game sudokuGame;
    sudokuGame.generateSudoku(difficultyLevel);

    cout << "\nInitial Sudoku Board:\n";
    sudokuGame.printSudoku();

    sudokuGame.play();

    return 0;
}

Ensuring Unique Solutions

Discussing the importance of generating puzzles with a unique solution and the techniques used to achieve this. the technique that is used for testing is “unit testing” and The importance of unit testing is to verify the functionality of individual components of the game.

Difficulty Levels

How to adjust the game’s difficulty levels by removing a certain number of cells from the puzzle and ensuring the game remains engaging and challenging.

Algorithms for Sudoku Generation and Solving

Explaining the algorithms used for generating puzzles and the backtracking algorithm for solving them. This will include how to apply these algorithms to ensure puzzles are challenging yet solvable.

Game Play Mechanics

Handling user inputs accurately and validating moves against the game’s rules are fundamental gameplay mechanics. The game progresses as players input their guesses, with each move requiring validation to ensure it adheres to Sudoku’s constraints.

Performance Optimization

Optimizing the game for performance involves efficient memory management and implementing speed enhancement techniques. Such optimizations ensure the game runs smoothly, providing an enjoyable experience for the user.

Conclusion

Concluding, this C++ Sudoku project exemplifies the application of DSA in game development, emphasizing problem-solving and programming skills. Future enhancements could include graphical UIs, multiplayer options, and advanced difficulty levels, further expanding the game’s appeal and functionality.

Source code of C++ project of sudoku game of DSA

#include <iostream>
#include <vector>

#define UNASSIGNED 0
#define N 9

using namespace std;

// Function to check whether it will be legal to assign num to the given row, col
bool isSafe(int grid[N][N], int row, int col, int num) {
    // Check if we find the same num in the similar row , we return false
    for (int x = 0; x <= 8; x++)
        if (grid[row][x] == num)
            return false;

    // Check if we find the same num in the similar column , we return false
    for (int x = 0; x <= 8; x++)
        if (grid[x][col] == num)
            return false;

    // Check if we find the same num in the particular 3*3 matrix, we return false
    int startRow = row - row % 3, startCol = col - col % 3;

    for (int i = 0; i < 3; i++)
        for (int j = 0; j < 3; j++)
            if (grid[i + startRow][j + startCol] == num)
                return false;

    return true;
}

// Takes a partially filled-in grid and attempts to assign values to all unassigned locations in such a way to meet the requirements for Sudoku solution (non-duplication across rows, columns, and boxes)
bool solveSudoku(int grid[N][N]) {
    int row, col;
    bool isEmpty = true;
    for (row = 0; row < N; row++) {
        for (col = 0; col < N; col++) {
            if (grid[row][col] == UNASSIGNED) {
                isEmpty = false;
                break;
            }
        }
        if (!isEmpty) {
            break;
        }
    }

    // No unassigned position is found, puzzle solved
    if (isEmpty) {
        return true;
    }

    // Consider digits 1 to 9
    for (int num = 1; num <= N; num++) {
        // Check if looks promising
        if (isSafe(grid, row, col, num)) {
            // Make tentative assignment
            grid[row][col] = num;

            // Return, if success
            if (solveSudoku(grid))
                return true;

            // Failure, unmake & try again
            grid[row][col] = UNASSIGNED;
        }
    }
    // This triggers backtracking
    return false;
}

// Utility function to print grid
void printGrid(int grid[N][N]) {
    for (int row = 0; row < N; row++) {
        for (int col = 0; col < N; col++)
            cout << grid[row][col] << " ";
        cout << endl;
    }
}

int main() {
    int grid[N][N] = {
        {5, 3, 0, 0, 7, 0, 0, 0, 0},
        {6, 0, 0, 1, 9, 5, 0, 0, 0},
        {0, 9, 8, 0, 0, 0, 0, 6, 0},
        {8, 0, 0, 0, 6, 0, 0, 0, 3},
        {4, 0, 0, 8, 0, 3, 0, 0, 1},
        {7, 0, 0, 0, 2, 0, 0, 0, 6},
        {0, 6, 0, 0, 0, 0, 2, 8, 0},
        {0, 0, 0, 4, 1, 9, 0, 0, 5},
        {0, 0, 0, 0, 8, 0, 0, 7, 9}
    };

    if (solveSudoku(grid) == true)
        printGrid(grid);
    else
        cout << "No solution exists";

    return 0;
}