【01背包问题】AcWing2.01背包问题

AcWing2.01背包问题

题解

二维

#include <iostream>

using namespace std;

const int N = 1010;

int dp[N][N];
int v[N], w[N];

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

一维

#include <iostream>

using namespace std;

const int N = 1010;

int dp[N];
int v[N], w[N];

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