Charm Bracelet（poj3624）（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 weightW_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<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
int main()
{
  int i,j,n,m;
  int a[3500],b[3500],dp[13000];
  while(scanf("%d %d",&n,&m)!=EOF)
  {
    for(i=1;i<=n;i++)
    {
      scanf("%d %d",&a[i],&b[i]);
    }
    memset(dp,0,sizeof(dp));
    for(i=1;i<=n;i++)
    {
      for(j=m;j>=a[i];j--)
      dp[j]=max(dp[j],dp[j-a[i]]+b[i]);
    }
    printf("%d\n",dp[m]);
  }
  return 0;
}