leetcode37:解数独

class Solution {
public:
    bool Sudoku(vector<vector<char>>& board){
        map<char,int> m;
        bool flag=false;
        for(int i=1;i<=9;i++){
            m['0'+i]+=1; 
        }
        int i,j;
        for(i=0;i<9;i++){
            for(j=0;j<9;j++){
                if(board[i][j]=='.'){
                    for(int k=0;k<9;k++){
                        if(board[i][k]!='.') m[board[i][k]]-=1;
                        if(board[k][j]!='.') m[board[k][j]]-=1;
                    }
                    for(int k=i/3*3;k<i/3*3+3;k++){
                        for(int t=j/3*3;t<j/3*3+3;t++){
                            if(board[k][t]!='.') m[board[k][t]]-=1;
                        } 
                    }
                    bool ok=false;
                    for(int k=1;k<=9;k++){
                        if(m['0'+k]>0){
                            ok=true;
                            board[i][j]='0'+k;
                            if(Sudoku(board)) return true;
                            else board[i][j]='.';
                        }
                    }
                    if(!ok||board[i][j]=='.') return false;
                    break;
                }
            }
        }
        if(i==9)  flag=true;
        return flag;
    }
    void solveSudoku(vector<vector<char>>& board) {
        Sudoku(board);
    }
};

由于数独固定9*9，大小不大，暴力回溯即可。

标签：Sudoku,false,int,return,bool,board,leetcode37,解数
来源： https://blog.csdn.net/SJTU_liangge/article/details/113815407