ZOJ 3211 Dream City（DP）

思路：按b值从小到大排序，然后就是简单DP了，因为值越大的肯定放后面转移，所以是可行的

代码:

#include <cstdio>#include <cstring>#include <algorithm>using namespace std;const int N = 255;int t, n, m;struct Tree {    int a, b;} tree[N];bool cmp(Tree a, Tree b) {     return a.b < b.b;}int dp[N][N];int main() {    scanf("%d", &t);    while (t--) {scanf("%d%d", &n, &m);for (int i = 1; i <= n; i++)    scanf("%d", &tree[i].a);for (int i = 1; i <= n; i++)    scanf("%d", &tree[i].b);sort(tree + 1, tree + 1 + n, cmp);for (int i = 1; i <= n; i++) {    for (int j = 1; j <= m; j++) {dp[i][j] = max(dp[i - 1][j], dp[i - 1][j - 1] + tree[i].a + tree[i].b * (j - 1));    }}printf("%d\n", dp[n][m]);    }    return 0;}