Sudoku POJ

Sudoku POJ - 2676

问题

传送门

我是抄的这篇题解传送门.

代码

#include <iostream>
#include <cstdio>
#include <queue>
#include <cstring>
using namespace std;
bool square[9][10],checkcol[9][10],checkrow[9][10];
int sudoku[9][9];
bool isdone;
void dfs(int i,int j)
{
    if(i==9)
    {
        isdone = true;
        for(int i=0;i<9;i++)
        {
            for(int j=0;j<9;j++)
            {
                cout << sudoku[i][j];
            }
            cout << "
";
        }
        return ;
    }
    if(isdone)
        return ;
    if(sudoku[i][j])
    {
        if(j==8)
            dfs(i+1,0);
        else
            dfs(i,j+1);
    }
    else
    {
        for(int num=1;num<10;num++)
        {
            int k = 3*(i/3) + j/3;
            if(!checkrow[i][num] && !checkcol[j][num] &&!square[k][num])
            {
                sudoku[i][j] = num;
                checkrow[i][num] = checkcol[j][num] = square[k][num] = true;
                if(j==8)
                    dfs(i+1,0);
                else
                    dfs(i,j+1);
                sudoku[i][j] = 0;
                checkrow[i][num] = checkcol[j][num] = square[k][num] = false;
            }
        }
    }

}
int main() {
    int t;
    cin >> t;
    while(t--)
    {
        memset(square,0, sizeof(square));
        memset(checkcol,0,sizeof(checkcol));
        memset(checkrow,0,sizeof(checkrow));
        for(int i=0;i<9;i++)
        {
            char tmp[9];
            cin >> tmp;
            for(int j=0;j<9;j++)
            {
                sudoku[i][j] = tmp[j] - '0';
                if(sudoku[i][j])
                {
                    int k = 3*(i/3) + j/3;
                    checkrow[i][sudoku[i][j]] = 1;
                    checkcol[j][sudoku[i][j]] = 1;
                    square[k][sudoku[i][j]] = 1;
                }
            }
        }
        isdone = false;
        dfs(0,0);
    }
    return 0;
}