题解luogu P1776 宝物筛选

Posted 2022-07-02 lovezxy520

一道多重背包问题，要二进制优化。

#include<bits/stdc++.h>
using namespace std;
int cnt, dp[100005], n, w[100005], v[100005], s, m, vv, ww;
int main()

    cin >> n >> m;
    for(int i = 1; i <= n; i++)
    
        cin >> ww >> vv >> s;
        for(int j = 1; j <= s; j <<= 1)
        
            v[++cnt] = j*vv;
            w[cnt] = j*ww;
            s -= j;
        
        if(s)
        
            v[++cnt] = s*vv;
            w[cnt] = s*ww;
        
    
    for(int i = 1; i <= cnt; i++)
        for(int j = m; j >= v[i]; j--)
            dp[j] = max(dp[j], dp[j-v[i]]+w[i]);
    cout << dp[m];
    return 0;