完全背包问题-朴素做法 y总-yyds-🐂🐂🐂🍺啊

#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 1010;
int f[N][N];
int w[N], v[N];
int n, m;

int main() {
    cin >> n >> m;
    for (int i = 1; i <= n ; i++) cin >> w[i] >> v[i];

    for (int i = 1;  i <= n; i++) {
        for (int j = 1; j <= m; j++) {
            f[i][j] = f[i - 1][j];
            if (j >= w[i]) f[i][j] = max(f[i][j], f[i][j - w[i]] + v[i]);
        }
    }
    cout << f[n][m] << endl;

    return 0;
}

一维空间优化-完全背包

#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 1010;
int f[N];
int w[N], v[N];
int n, m;

int main() {
    cin >> n >> m;
    for (int i = 1; i <= n ; i++) cin >> w[i] >> v[i];

    for (int i = 1;  i <= n; i++) {
        for (int j = w[i]; j <= m; j++) {//从小到大，是因为上面朴素做法中用的是同一层的状态更新的
            f[j] = max(f[j], f[j - w[i]] + v[i]);  
        }
    }
    cout << f[m] << endl;

    return 0;
}