题干：

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

解题报告：

    可以说是十分裸题了。0-1背包

AC代码：

//0-1裸题
#include <cstdio>
#include <algorithm>
#include <cstring>
#include<iostream>
#include <queue>
using namespace std;
int w[100000],v[100000];
int dp[100000];
int n,m; 
int main()
{
	while(cin>>n>>m) {
		for(int i = 1; i<=n; i++) {
			cin>>w[i]>>v[i];
		}
		for(int i = 1; i<=n; i++) {
			for(int j = m; j>=w[i]; j--) {
				dp[j] = max(dp[j],dp[j-w[i]] + v[i]);
			}
		}
		cout<<dp[m]<<endl;
	}
	
	return 0 ;
}