Charm Bracelet（01背包）

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 W_i (1 ≤ W_i ≤ 400), a 'desirability' factor D_i (1 ≤ D_i ≤ 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.

Input

* Line 1: Two space-separated integers: N and M
* Lines 2..N+1: Line i+1 describes charm i with two space-separated integers: W_i and D_i

Output

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

Sample Input

4 6
1 4
2 6
3 12
2 7

Sample Output

23
题目大意：
给定n个物品，m的最大承重，求在承重范围之内的最大的D的和。
01背包模板

#include <iostream>
#include <algorithm>
using namespace std;
int w[3405],d[3405],dp[12885];
int n,m;
int main()
{
    cin>>n>>m;
    for(int i=1;i<=n;i++)
        cin>>w[i]>>d[i];
    for(int i=1;i<=n;i++)
        for(int j=m;j>=w[i];j--)
            dp[j]=max(dp[j],dp[j-w[i]]+d[i]);
    cout<<dp[m]<<'
';
    return 0;
}