Poj3624 Charm Bracelet （01背包）

题目链接：http://poj.org/problem?id=3624

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

 

二维dp数组会超内存，得使用优化后的一维dp数组

#include <iostream>
#include <algorithm>
using namespace std;
int n,m;
int v[3500];
int w[3500];
int dp[13000];
int main()
{
    while(cin>>n>>m){
        for(int i=0;i<n;i++){
            cin>>w[i]>>v[i];
        }
        for(int i=0;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;
}