poj 3624(01背包)

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

Source

USACO 2007 December Silver

//裸的01背包

#include <iostream>
#include <stdio.h>
#include <string.h>
using namespace std;
int w[4000],v[4000];
int dp[12885];
int n,m;
void ZeroOnePack(int w,int v)
{
    for(int i=m;i>=w;i--)
        dp[i]=max(dp[i],dp[i-w]+v);
}
int main()
{
    while(~scanf("%d%d",&n,&m))
    {
        memset(dp,0,sizeof(dp));
        for(int i=1;i<=n;i++)
            scanf("%d%d",w+i,v+i);
        for(int i=1;i<=n;i++)
            ZeroOnePack(w[i],v[i]);
        printf("%d\n",dp[m]);
    }

    return 0;
}