01背包

一、思路

二、代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
using namespace std;
int f[1010][1010], w[1010], v[1010];

int main() {
    int n, t;
    cin >> n >> t;
    for (int i = 1; i <= n; i++) cin >> v[i] >> w[i];
    
    for (int i = 1; i <= n; i++)
        for (int j = 0; j <= t; j++) {
            f[i][j] = f[i - 1][j];
            if (j >= v[i]) f[i][j] = max(f[i][j], f[i - 1][j - v[i]] + w[i]);
        }
            
            
    cout << f[n][t] << endl;
    return 0;
}

三、优化思路

四、优化代码

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
#include <bits/stdc++.h>
using namespace std;
int f[1010], w[1010], v[1010];

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