>代码有问题，在返回的时候
 #include <iostream>
> #include <cstdio>
> #include <cstring>
> using namespace std;
> 
> #define M 11
> 
> struct point { int x, y; } p[100];
> 
> char map[M][M];
> bool row[M][M], col[M][M], mat[3][3][M];
> int np;
> 
> void DFS(int num)
> {
>     int i, j;
> 
>     if (num == np) {
>         for (i = 0; i < 9; i++) {
>             for (j = 0; j < 9; j++)
>                 printf ("%c", map[i][j]);
>             printf ("\n");
>         }
>         return;
>     }
> 
>     for (i = 1; i <= 9; i++) {
>         int x = p[num].x;
>         int y = p[num].y;
>         if (!row[x][i] && !col[y][i] && !mat[x/3][y/3][i]) {
>             row[x][i] = col[y][i] = mat[x/3][y/3][i] = true;
>             map[x][y] = '0' + i;
>             DFS(num+1);
>             row[x][i] = col[y][i] = mat[x/3][y/3][i] = false;
>             map[x][y] = '0';
>         }
>     }
> }
> 
> int main()
> {
>     int t, i, j;
> 
>     scanf ("%d", &t);
>     getchar();
>     while (t--) {
>         memset (row, false, sizeof (row));
>         memset (col, false, sizeof (col));
>         memset (mat, false, sizeof (mat));
>         np = 0;
>         for (i = 0; i < 9; i++) {
>             gets(map[i]);
>             for (j = 0; j < 9; j++) {
>                 int num = map[i][j] - '0';
>                 if (num)
>                     row[i][num] = col[j][num] = mat[i/3][j/3][num] = true;
>                 else {
>                     p[np].x = i;
>                     p[np++].y = j;
>                 }
>             }
>         }
>         DFS(0);
>     }
>     return 0;
> }