题解

很简单

#include<iostream>
using namespace std;
int main(){
    int n, k;
    cin >> n >> k;
    int a[1000001], p[1000001];
    for(int i = 1; i <= n; i++){
        cin >>a[i];
        p[i] = a[i] + p[i - 1];
    } 
    int mw = 0;
    for(int i = k + 1; i <= n; i++){
        int c = p[i] - p[i - k - 1];
        mw = max(mw, c);
    }
    cout << mw;
    return 0;
}