Sudoku
Time Limit: 3000/1000 MS (Java/Others) Memory Limit: 65535/65535 K (Java/Others)
Total Submission(s): 596 Accepted Submission(s): 216
Actually, Yi Sima was playing it different. First of all, he tried to generate a 4×4 board with every row contains 1 to 4, every column contains 1 to 4. Also he made sure that if we cut the board into four 2×2 pieces, every piece contains 1 to 4.
Then, he removed several numbers from the board and gave it to another guy to recover it. As other counselors are not as smart as Yi Sima, Yi Sima always made sure that the board only has one way to recover.
Actually, you are seeing this because you've passed through to the Three-Kingdom Age. You can recover the board to make Yi Sima happy and be promoted. Go and do it!!!
It's guaranteed that there will be exactly one way to recover the board.
****
2341
4123
3214
*243
*312
*421
*134
*41*
**3*
2*41
4*2*
1432
2341
4123
3214
Case #2:
1243
4312
3421
2134
Case #3:
3412
1234
2341
4123
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
using namespace std;
bool row[][];
bool col[][];
bool squ[][];
int a[][];
int ans[][]; int pos(int x, int y) {
return (x/) * + (y/);
}
bool flag;
void dfs(int x, int y) {
if (flag) return;
if (y > ) y = , x++;
if (x > ) {
for (int i = ; i <= ; i++)
for (int j = ; j <= ; j++) ans[i][j] = a[i][j];
flag = true;
return;
}
if (a[x][y] != ) {
dfs(x, y+);
return;
}
for (int i = ; i <= ; i++) {
if (row[x][i]) continue;
if (col[y][i]) continue;
int z = pos(x, y);
if (squ[z][i]) continue;
row[x][i] = true;
col[y][i] = true;
squ[z][i] = true;
a[x][y] = i;
dfs(x, y+);
a[x][y] = ;
row[x][i] = false;
col[y][i] = false;
squ[z][i] = false;
}
}
char s[];
int main() {
//freopen("h.in", "r",stdin);
int T, cas = ;
scanf("%d", &T);
while (T--) {
printf("Case #%d:\n", ++cas);
for (int i = ; i <= ; i++) {
scanf("%s", s+);
for (int j = ; j <= ; j++) {
if (s[j] == '*') a[i][j] = ;
else a[i][j] = s[j] - '';
}
}
memset(col,,sizeof(col));
memset(row,,sizeof(row));
memset(squ,,sizeof(squ));
memset(ans,,sizeof(ans));
for (int i = ; i <= ; i++) {
for (int j = ; j <= ; j++) {
if (a[i][j] == ) continue;
row[i][a[i][j]] = true;
col[j][a[i][j]] = true;
int z = pos(i, j);
squ[z][a[i][j]] = true;
}
}
flag = false;
dfs(, );
for (int i = ; i <= ; i++) {
for (int j = ; j <= ; j++) printf("%d",ans[i][j]);
printf("\n");
}
}
}