【正经题解】水壶

#include<iostream>
using namespace std;

const int MAX_N = 1000001;

int waterAmount[MAX_N], prefixSum[MAX_N];

int main(){
    int n, k;
    cin >> n >> k;

    // 读入水壶的初始装水量，并计算前缀和
    for(int i = 1; i <= n; i++){
        cin >> waterAmount[i];
        prefixSum[i] = waterAmount[i] + prefixSum[i - 1];
    } 

    int maxWater = 0;

    // 遍历可能的操作次数范围
    for(int i = k + 1; i <= n; i++){
        // 计算每次操作后的水量
        int currentWater = prefixSum[i] - prefixSum[i - k - 1];
        
        // 更新最大水量
        maxWater = max(maxWater, currentWater);
    }

    cout << maxWater;

    return 0;
}