【HDOJ】2487 Ugly Windows

暴力解。

 #include <cstdio>
 #include <cstring>

 #define MAXN 105

 char map[MAXN][MAXN];
 char visit[];
 int n, m;

 bool check(char c) {
     int i, j;
     int x1=MAXN, y1=MAXN, x2=-, y2=-;

     for (i=; i<n; ++i) {
         for (j=; j<m; ++j) {
             if (map[i][j] == c) {
                 if (i<x1)   x1 = i;
                 if (j<y1)   y1 = j;
                 if (i>x2)   x2 = i;
                 if (j>y2)   y2 = j;
             }
         }
     }
     if (x2-x1< || y2-y1<)
         return false;
     for (i=x1; i<=x2; ++i)
         if (map[i][y1]!=c || map[i][y2]!=c)
             return false;
     for (j=y1; j<=y2; ++j)
         if (map[x1][j]!=c || map[x2][j]!=c)
             return false;
     for (i=x1+; i<x2; ++i)
         for (j=y1+; j<y2; ++j)
             if (map[i][j] != '.')
                 return false;
     return true;
 }

 int main() {
     int i;
     int j;

     while (scanf("%d %d", &n, &m)!=EOF && (n||m)) {
         memset(visit, false, sizeof(visit));
         for (i=; i<n; ++i) {
             scanf("%s", map[i]);
             for (j=; j<m; ++j) {
                 if (map[i][j] != '.') {
                     visit[map[i][j]-'A'] = true;
                 }
             }
         }
         for (i=; i<; ++i) {
             if (visit[i] && check(i+'A'))
                 printf("%c", i+'A');
         }
         printf("\n");
     }

     return ;
 }