题解 | 瞌睡

import java.util.*;
import java.lang.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int n = in.nextInt();
            int k = in.nextInt();
            int[] inte = new int[n];
            int[] clear = new int[n];
            int score = 0;
            for(int i=0;i<n;i++) inte[i] = in.nextInt();
            for(int i=0;i<n;i++) {
                clear[i] = in.nextInt();
                if(clear[i]>0) {
                    score+=inte[i];
                    inte[i] = 0;
                }
            }
            int[] preSum = new int[n+1];
            preSum[n] = 0;
            for(int i=n-1;i>=n-k;i--) preSum[i] = preSum[i+1]+inte[i];
            for(int i=n-k-1;i>=0;i--)  preSum[i] = inte[i]+preSum[i+1]-inte[i+k];
            //  System.out.print(Arrays.toString(preSum));
            System.out.print(Arrays.stream(preSum).max().getAsInt()+score);
        }
    }
}

核心思路：后缀和（前缀和反向）