HDU ACM 2844 Coins (多重背包)----------------01背包,完全背包,多重背包模板

http://acm.hdu.edu.cn/showproblem.php?pid=2844

 

多重背包问题.

求出恰好能买的数目.最后找f[i]>0的背包有几个

或者

不需要恰好装满,最后搜索f[i] == i 的数目

#include <iostream>
using namespace std;
const int MAX = 100000 + 10;
const int INF = 0x7fffffff;
int f[MAX];
int v;
void ZeroOnePack(int cost,int weight)
{
    int i;
    for(i=v;i>=cost;i--)
    {
        f[i] = max(f[i],f[i-cost]+weight);
    }
}
void CompletePack(int cost,int weight)
{
    int i;
    for(i=cost;i<=v;i++)
    {
        f[i] = max(f[i],f[i-cost]+weight);
    }
}
void MultiplePack(int cost,int weight,int amount)
{
    if(v <= cost*amount)
    {
        CompletePack(cost,weight);
        return;
    }
    else
    {
        int k = 1;
        while(k<amount)
        {
            ZeroOnePack(k*cost,k*weight);
            amount = amount - k;
            k = k*2;
        }
        ZeroOnePack(amount*cost,amount*weight);
    }
}
int main()
{
    int n;
    while(cin>>n>>v,n+v)
    {
        int c[MAX];
        int a[MAX];
        int i;
        for(i=0;i<n;i++)
        {
            cin>>c[i];
        }
        for(i=0;i<n;i++)
        {
            cin>>a[i];
        }
        for(i=0;i<=v;i++)
        {
            f[i] = -1*INF;
        }
        f[0] = 0;
        for(i=0;i<n;i++)
        {
            MultiplePack(c[i],c[i],a[i]);
        }
        int sum = 0;
        for(i=1;i<=v;i++)
        {
            if(f[i] > 0)
            {
                sum++;
            }
        }
        cout<<sum<<endl;
    }
    return 0;
}