题目描述

Bessie has gone to the mall's jewelry store and spies a charm bracelet. Of course, she'd like to fill it with the best charms possible from the N (1 ≤ N ≤ 3,402) available charms. Each charm i in the supplied list has a weight Wi (1 ≤ Wi ≤ 400), a 'desirability' factor Di (1 ≤ Di ≤ 100), and can be used at most once. Bessie can only support a charm bracelet whose weight is no more than M (1 ≤ M ≤ 12,880).

Given that weight limit as a constraint and a list of the charms with their weights and desirability rating, deduce the maximum possible sum of ratings.

有N件物品和一个容量为V的背包。第i件物品的重量是c[i]，价值是w[i]。求解将哪些物品装入背包可使这些物品的重量总和不超过背包容量，且价值总和最大。

输入输出格式

输入格式：

* Line 1: Two space-separated integers: N and M

* Lines 2..N+1: Line i+1 describes charm i with two space-separated integers: Wi and Di

第一行：物品个数N和背包大小M

第二行至第N+1行：第i个物品的重量C[i]和价值W[i]

输出格式：

* Line 1: A single integer that is the greatest sum of charm desirabilities that can be achieved given the weight constraints

输出一行最大价值。

输入输出样例

4 6
1 4
2 6
3 12
2 7

23


01背包模板

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cmath>
 4 #include<algorithm>
 5 #include<cstring>
 6 using namespace std;
 7 
 8 int m,n,w[3403],c[3403],f[3403][12881];
 9 
10 int main()
11 {
12     scanf("%d%d",&n,&m);
13     for (int i=1; i<=n; ++i)
14         scanf("%d%d",&w[i],&c[i]);
15     for (int i=1; i<=n; ++i)
16         for (int j=m; j>0; --j)
17         {
18             if (w[i] <= j)
19                 f[i][j] = max(f[i-1][j],f[i-1][j-w[i]]+c[i]);
20             else f[i][j] = f[i-1][j];
21         }
22     printf("%d",f[n][m]);
23     return 0;
24 }