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。

 /**************************************************************
     Problem: 1218
     User: rausen
     Language: C++
     Result: Accepted
     Time:2860 ms
     Memory:98656 kb
 ****************************************************************/

 #include <cstdio>
 #include <cmath>
 #include <algorithm>

 using namespace std;

 int a[][];

 int main(){
     int n, R, x, y, c, i, j, ans = , maxc = ;
     scanf("%d%d", &n ,&R);
     while (n--){
         scanf("%d%d%d", &x, &y, &c);
         a[x + ][y + ] = c;
     }
     for (int i = ; i < maxc; ++i)
         for (int j = ; j < maxc; ++j)
             a[i][j] += a[i - ][j] + a[i][j - ] - a[i - ][j - ];
     maxc -= R;
     for (int i = ; i < maxc; ++i)
         for (int j = ; j < maxc; ++j)
             ans = max(ans, a[i + R][j + R] + a[i][j] - a[i + R][j] - a[i][j + R]);
     printf("%d\n", ans);
     return ;
 }