BZOJ1218 [HNOI2003]激光炸弹

题目后面写着DP就当它是DP吧。。

本来是扫描线+线段树的说，但是捏5000^2还是能过滴，于是暴力枚举正方形+所谓的DP就解决了。

 

 1 /**************************************************************
 2     Problem: 1218
 3     User: rausen
 4     Language: C++
 5     Result: Accepted
 6     Time:2860 ms
 7     Memory:98656 kb
 8 ****************************************************************/
 9  
10 #include <cstdio>
11 #include <cmath>
12 #include <algorithm>
13  
14 using namespace std;
15  
16 int a[5005][5005];
17  
18 int main(){
19     int n, R, x, y, c, i, j, ans = 0, maxc = 5002;
20     scanf("%d%d", &n ,&R);
21     while (n--){
22         scanf("%d%d%d", &x, &y, &c);
23         a[x + 1][y + 1] = c;
24     }
25     for (int i = 1; i < maxc; ++i)
26         for (int j = 1; j < maxc; ++j)
27             a[i][j] += a[i - 1][j] + a[i][j - 1] - a[i - 1][j - 1];
28     maxc -= R;
29     for (int i = 0; i < maxc; ++i)
30         for (int j = 0; j < maxc; ++j)
31             ans = max(ans, a[i + R][j + R] + a[i][j] - a[i + R][j] - a[i][j + R]);
32     printf("%d\n", ans);        
33     return 0;   
34 }
View Code

 

posted on 2014-09-28 18:30  Xs酱~  阅读(331)  评论(0)  编辑  收藏  举报