POJ3624 01背包入门

还是入门题，只不过需要优化一下空间，不然就会内存超限

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

#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<string.h>
using namespace std;
int dp[15000];
int main()
{
    int n,w,c,val;
    cin>>n>>w;
    for(int i=1;i<=n;i++)
    {
        scanf("%d%d",&c,&val);
        for(int j=w;j>=c;j--)
        {
            dp[j]=max(dp[j],dp[j-c]+val);
        }
    }
    cout<<dp[w]<<endl;
}