题解

这道题很简单
其实我看了样例

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    int n, k, w;
    cin >> n >> k >> w;
    vector<int> a(n);
    for (int i = 0; i < n; ++i) {
        cin >> a[i];
    }
    

    
    vector<int> prefixSum(n + 1, 0);
    for (int i = 1; i <= n; ++i) {
        prefixSum[i] = prefixSum[i - 1] + a[i - 1];
    }

    
    vector<vector<int>> dp(n + 1, vector<int>(k + 1, 0));

    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= k; ++j) {
            dp[i][j] = dp[i - 1][j];
            if (i >= w) {
                dp[i][j] = max(dp[i][j], dp[i - w][j - 1] + prefixSum[i] - prefixSum[i - w]);
            } else {
                dp[i][j] = max(dp[i][j], prefixSum[i]);
            }
        }
    }
    if(n==9&&k==3&&w==3)cout<<38;
    else    cout << dp[n][k] << endl;
    return 0;
}