内存:64  时间:1

题目描述

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.

输入

* 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

输出

* Line 1: A single integer that is the greatest sum of charm desirabilities that can be achieved given the weight constraints

样例输入

4 6
1 4
2 6
3 12
2 7

样例输出

23

提示

01背包问题,需要使用滚动数组进行优化,不然内存超限。

代码如下

#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
    int n,m,i,j;
    int w[3500],p[3500];
    while(cin>>n>>m)
    {
        int c[20000]={0};
        for(i=1;i<=n;i++)
            cin>>w[i]>>p[i];
        for(i=1;i<=n;i++)
            for(j=m;j>=w[i];j--)
                c[j]=max(c[j],c[j-w[i]]+p[i]);
        cout<<c[m]<<endl;
    }
    return 0;
}

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