Sudoku Solver

最新推荐文章于 2025-05-31 23:57:32 发布

原创最新推荐文章于 2025-05-31 23:57:32 发布 · 800 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#Sudoku Solver

leetcode 专栏收录该内容

27 篇文章

订阅专栏

本文介绍了一种通过编程解决数独谜题的方法。利用回溯算法填充空格，并通过验证函数确保每一步操作都符合数独规则。该算法能够找到唯一解并标记在数独盘面上。

Write a program to solve a Sudoku puzzle by filling the empty cells.

Empty cells are indicated by the character '.'.

You may assume that there will be only one unique solution.

A sudoku puzzle...

...and its solution numbers marked in red.

解：

bool isValid(vector<vector<char>> & board, int x, int y){
        for(int i=0; i<board.size(); i++){
            if(board[i][y]=='.' || i==x)
                continue;
            if(board[x][y]==board[i][y])
                return false;
        }
        
        for(int i=0; i<board[0].size(); i++){
            if(board[x][i]=='.' || i==y)
                continue;
            if(board[x][y]==board[x][i])
                return false;
        }
        
        int startx=x/3*3;
        int starty=y/3*3;
        for(int i=startx; i<startx+3; i++){
            for(int j=starty; j<starty+3; j++){
                if(board[i][j]=='.' || i==x || j==y)
                    continue;
                if(board[i][j]==board[x][y])
                    return false;
            }
        }
        return true;
    }

    bool solveSudo(vector<vector<char>>& board) {
        for(int i=0; i<board.size(); i++){
            for(int j=0; j<board[0].size(); j++){
                if(board[i][j]!='.')
                    continue;
                int k;
                for(k=1; k<10; k++){
                    board[i][j]=k+'0';
                    if(isValid(board, i, j))
                    {
                        if(solveSudo(board))
                            return true;
                    }
                    board[i][j]='.';
                }
                return false;//没有任何判断，直接返回false
            }
        }
        return true;
    }
    
    void solveSudoku(vector<vector<char>>& board) {
        solveSudo(board);
    }