poj-3624-Charm Bracelet

01背包问题

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 Wi (1
≤ Wi≤ 400), a 'desirability' factor Di (1 ≤ Di ≤ 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: Wi and Di

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<cstring>
#define max1(a,b) a>b?a:b
using namespace std;
int a[12885],b[12885],c[12885];
int main()
{
int n,m,i,j;
while(cin>>n>>m)
{
for(i=1;i<=n;i++)
cin>>b[i]>>c[i];
memset(a,0,sizeof(a));
for(i=1;i<=n;i++)
for(j=m;j>=b[i];j--)
a[j]=max1(a[j],a[j-b[i]]+c[i]);
cout<<a[m]<<endl;
}
return 0;
}