庆功会 https://www.acwing.com/problem/content/1021/

朴素版一/二维写法 + 二进制优化版

#include <iostream>
using namespace std;

const int N = 6010;
int f[N][N], v[N], w[N], s[N], n, m;

int main()
{
    cin >> n >> m;
    for ( int i = 1; i <= n; i ++ ) cin >> v[i] >> w[i] >> s[i];
    for ( int i = 1; i <= n; i ++ )     
        for ( int j = 0; j <= m; j ++ )
            for ( int k = 0; k <= s[i] && k * v[i] <= j; k ++) 
                f[i][j] = max(f[i][j], f[i - 1][j - k * v[i]] + k * w[i]);
    cout << f[n][m];
    return 0;
}

一维写法

#include <iostream>
using namespace std;

const int N = 6010;
int f[N], n, m;

int main()
{
    cin >> n >> m;
    for ( int i = 1; i <= n; i ++ ) 
    {
        int v, w, s;
        cin >> v >> w >> s;
        for ( int j = m; j >= 0; j -- )     //从大到小
            for ( int k = 0; k <= s && k * v <= j; k ++ )
                f[j] = max(f[j], f[j - k * v] + w * k);
    }
    cout << f[m];
    return 0;
}

二进制优化

#include <iostream>
using namespace std;

const int N = 5010, M = 6010;
int f[M], v[N], w[N];
int n, m, p;

int main()
{
    cin >> n >> m;
    while ( n -- )
    {
        int a, b, s, k = 1;
        cin >> a >> b >> s;
        while ( k <= s )
        {
            v[++ p] = k * a;
            w[p] = k * b;
            s -= k;
            k *= 2;
        }
        if ( s > 0 ) 
        {
            v[++ p] = s * a;
            w[p] = s * b;
        }
    }
    for ( int i = 1; i <= p; i ++ ) 
        for ( int j = m; j >= v[i]; j -- )
            f[j] = max(f[j], f[j - v[i]] + w[i]);
    cout << f[m];
    return 0;
}