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背包01

• 01背包

代码块

int dp[1004][1004], v[1004], w[1004];
int main()
{
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= n; ++i) {
        cin >> v[i] >> w[i];
    }
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) {
            dp[i][j] = dp[i - 1][j];
            if (j >= v[i]) {
                dp[i][j] = max(dp[i - 1][j], dp[i - 1][j - v[i]] + w[i]);
            }
        }
    }
    cout << dp[n][m];
    return 0;
}

优化

int dp[1004], v[1004], w[1004];
int main()
{
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= n; ++i) {
        cin >> v[i] >> w[i];
    }
    for (int i = 1; i <= n; ++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;
}

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