【HDOJ】1510 White Rectangles

这个题目很好，变形的题目也很多。简单DP。

 1 /* 1510 */
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <cstdlib>
 5
 6 #define MAXN 105
 7
 8 char map[MAXN][MAXN];
 9 int dp[MAXN][MAXN];
10
11 int min(int a, int b) {
12     return a<b ? a:b;
13 }
14
15 int main() {
16     int n;
17     int i, j, k, tmp;
18     int sum;
19
20     #ifndef ONLINE_JUDGE
21         freopen("data.in", "r", stdin);
22     #endif
23
24     while (scanf("%d", &n) != EOF) {
25         for (i=1; i<=n; ++i)
26             scanf("%s", map[i]+1);
27
28         sum = 0;
29         for (i=1; i<=n; ++i) {
30             for (j=1; j<=n; ++j) {
31                 if (map[i][j] == ‘#‘) {
32                     dp[i][j] = 0;
33                 } else {
34                     dp[i][j] = dp[i-1][j] + 1;
35                     tmp = dp[i][j];
36                     sum += tmp;
37                     for (k=j-1; k>0; --k) {
38                         tmp = min(tmp, dp[i][k]);
39                         sum += tmp;
40                     }
41                 }
42             }
43         }
44         printf("%d\n", sum);
45     }
46
47     return 0;
48 }