UVa11520 Fill the Square (字典序枚举)

链接：http://vjudge.net/problem/18268

分析：从上到下从左到右按字典序从小到大枚举。

 1 #include <cstdio>
 2
 3 const int maxn = 10 + 5;
 4
 5 int n;
 6 char grid[maxn][maxn];
 7
 8 int main() {
 9     int T;
10     scanf("%d", &T);
11     for (int kase = 1; kase <= T; kase++) {
12         scanf("%d", &n);
13         for (int i = 0; i < n; i++) scanf("%s", grid[i]);
14         for (int i = 0; i < n; i++)
15             for (int j = 0; j < n; j++) if (grid[i][j] == ‘.‘)
16                 for (char ch = ‘A‘; ch <= ‘Z‘; ch++) {
17                     if (i > 0 && grid[i - 1][j] == ch) continue;
18                     if (i < n - 1 && grid[i + 1][j] == ch) continue;
19                     if (j > 0 && grid[i][j - 1] == ch) continue;
20                     if (j < n - 1 && grid[i][j + 1] == ch) continue;
21                     grid[i][j] = ch; break;
22                 }
23         printf("Case %d:\n", kase);
24         for (int i = 0; i < n; i++) printf("%s\n", grid[i]);
25     }
26     return 0;
27 }