POJ_2676 Sudoku（DFS）

　　写了整整一天，到晚上才出过样例，然后各种wa， tle ，ole ！！！

code:

#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

const int N = 11;

char map[N][N];
int hr[N][N];
int hc[N][N];
int hx[3][3][N];
int z;

void dfs(int i, int j){
    int x, y, k, l;
    if( i < 0 && z){
        for(k = 0; k < 9; k++){
            for(l = 0; l < 9; l++){
                printf("%c", map[k][l]);
            }
            printf("\n");
        }
        z = 0;
        return ;
    }

    if(map[i][j] != '0' && z){
        x = i;
        y = j - 1;
        if(y < 0){
            y = 8; x = i-1;
        }
        dfs(x, y);
    } else {
        for(k = 1; k <= 9 && z; k++){
            if(!hr[i][k] && !hc[j][k] && !hx[i/3][j/3][k]){
                hr[i][k] = hc[j][k] = hx[i/3][j/3][k] = 1;
                map[i][j] = k + '0';
                x = i; y = j-1;
                if(y < 0){
                    y = 8; x = i-1;
                }
                //cout << x << ' ' << y << endl;
                dfs(x, y);
                hr[i][k] = hc[j][k] = hx[i/3][j/3][k] = 0;
                map[i][j] = '0';
            }
        }
    }
}

int main(){
    //freopen("data.in", "r", stdin);

    int t, i, j;
    scanf("%d", &t);
    while(t--){
        char s[10];
        for(i = 0; i < 9; i++){
            scanf("%s", s);
            for(j = 0; j < 9; j++){
                map[i][j] = s[j];
            }
        }

        memset(hr, 0, sizeof(hr));
        memset(hc, 0, sizeof(hc));
        memset(hx, 0, sizeof(hx));

        for(i = 0; i < 9; i++){
            for(j = 0; j < 9; j++){
                if(map[i][j] != '0'){
                    hr[i][map[i][j]-'0'] = 1;
                    hx[i/3][j/3][map[i][j]-'0'] = 1;
                }
            }
        }
        for(j = 0; j < 9; j++){
            for(i = 0; i < 9; i++)
                if(map[i][j] != '0')
                    hc[j][map[i][j]-'0'] = 1;
        }z = 1;
        dfs(8, 8);
    }
    return 0;
}