【美团笔试题】连续最大子序列整除k

【思路】

滑动窗口“掐头去尾”

【正确代码】

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            int n = sc.nextInt();
            int[] arr = new int[n];
            for (int i = 0; i < n; i++) {
                arr[i] = sc.nextInt();
            }
            int k = sc.nextInt();
            for (int i = n; i > 0; i--) {//记录元素个数
                int sum = 0;
                for (int j = 0; j < i; j++) {
                    sum += arr[j];

                }
                if (sum % k == 0) {
                    System.out.println(i);
                    return;
                }
                for (int j = 1; j < n - i; j++) {//滑动只需要n-i次循环
                    sum = sum + arr[j - 1 + i] - arr[j - 1];
                    if (sum % k == 0) {
                        System.out.println(i);
                        return;
                    }
                }
            }
            System.out.println(0);
            return;
        }
    }
}