poj3624 Charm Bracelet

Description

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

01背包问题　
#include<stdio.h>

int c[3500],w[3500],f[13000];
int main()
{
	int i,j,k,n,v,m;
	while(scanf("%d%d",&n,&m)!=EOF)
	{
		for(i=0;i<=m;i++)
			f[i]=0;
		for(i=0;i<n;i++)
			scanf("%d%d",c+i,w+i);
		for (i = 0; i < n; ++i)
		{
			for (v = m; v >= c[i]; --v) //c[i]可优化为bound,bound = max {V - sum c[i,...n],c[i]}
			{
				f[v] = (f[v] > f[v - c[i]] + w[i]?f[v] : f[v - c[i]] + w[i]);
			}
		}
		printf("%d\n",f[m]);
	}
}