POJ-3624 01背包入门

还是入门题，只不过需要优化一下空间，不然就会内存超限

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

 1 #include<iostream>
 2 #include<stdio.h>
 3 #include<algorithm>
 4 #include<string.h>
 5 using namespace std;
 6 int dp[15000];
 7 int main()
 8 {
 9     int n,w,c,val;
10     cin>>n>>w;
11     for(int i=1;i<=n;i++)
12     {
13         scanf("%d%d",&c,&val);
14         for(int j=w;j>=c;j--)
15         {
16             dp[j]=max(dp[j],dp[j-c]+val);
17         }
18     }
19     cout<<dp[w]<<endl;
20 }