题目链接：uva 1419 - Ugly Windows
题目大意：给出一张图，模仿电脑窗口，问有哪些窗口未被其他窗口覆盖。
解题思路：水题，先找到一个点，然后枚举出长宽，再判断框框和框框里面。注意样例中的特殊情况，左上角被覆盖。
#include#include const int N = 105; int r, c, v[N]; char g[N][N]; bool judge(int x, int y, int l, int w) { if (w - x < 2 || l - y < 2) return false; for (int i = y; i < l; i++) if (g[w-1][i] != g[x][y]) return false; for (int i = x; i < w; i++) if (g[i][l-1] != g[x][y]) return false; for (int i = x + 1; i < w - 1; i++) { for (int j = y + 1; j < l - 1; j++) if (g[i][j] != '.') return false; } return true;; } void solve() { for (int i = 0; i < r; i++) { for (int j = 0; j < c; j++) if (g[i][j] != '.' && v[g[i][j] - 'A'] == 0) { v[g[i][j]-'A'] = 1; int l = j, w = i; while (g[i][l] == g[i][j]) l++; while (g[w][j] == g[i][j]) w++; if (judge(i, j, l, w)) v[g[i][j]-'A'] = 2; } } } int main() { while (scanf("%d%d%*c", &r, &c) == 2 && r + c) { memset(v, 0, sizeof(v)); for (int i = 0; i < r; i++) gets(g[i]); solve(); for (int i = 0; i < 30; i++) if (v[i] == 2) printf("%c", 'A' + i); printf("\n"); } return 0; }