[DP] [51nod]1086 背包问题 V2

将多重背包展开为01背包

#pragma GCC optimize(2)
#include <cstdio>
#include <iostream>
using namespace std;
typedef long long ll;

const int MAXN = 1e6 + 10;

int volume[MAXN] = {0}, value[MAXN] = {0}, dp[MAXN] = {0};

int main()
{
    ios::sync_with_stdio(false);

    cin.tie(0);     cout.tie(0);

    int len, sumvolume, tf = 1, tmp;

    int tvol, tval, tpre;

    cin>>len>>sumvolume;

    while(len--)
    {
        cin>>tvol>>tval>>tpre;

        for(int i = 1; i <= tpre; i++)
        {
            volume[tf] = tvol;
            value[tf++] = tval;
        }
    }

    for(int i = 1; i < tf; i++)
    {
        for(int j = sumvolume; j >= volume[i]; j--)
        {
            tmp = dp[j - volume[i]] + value[i];
            if(tmp > dp[j])
                dp[j] = tmp;
            //dp[j] = max(dp[j], dp[j - volume[i]] + value[i]);
        }
    }

    cout<<dp[sumvolume]<<endl;

    return 0;
}