模板多重背包

Posted 2020-11-29 lovezxy520

二进制优化

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstdlib>
#include<cmath>
using namespace std;
const int maxn = 25000;
const int maxm = 2005;
int dp[maxn], vv, s[maxm], v1[maxm], w1[maxm];
int v2[maxn], w2[maxn];
int cnt, n;
int main()
{
    cin >> n >> vv;
    for(int i = 1; i <= n; i++)
        cin >> v1[i] >> w1[i] >> s[i];
    for(int i = 1; i <= n; i++)
    {
        for(int j = 1; j <= s[i]; j <<= 1)
        {
            v2[++cnt] = j*v1[i];
            w2[cnt] = j*w1[i];
            s[i] -= j;
        }
        if(s[i])
        {
            v2[++cnt] = s[i]*v1[i];
            w2[cnt] = s[i]*w1[i];
        }
    }
    for(int i = 1; i <= cnt; i++)
        for(int j = vv; j >= v2[i]; j--)
            dp[j] = max(dp[j], dp[j-v2[i]]+w2[i]);
    cout << dp[vv];
    return 0;
}