3-3 슬라이딩 문제

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Scanner;

class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] arr = new int[n];
		int k = sc.nextInt();
		for(int i=0; i<n; i++) {
			arr[i]=sc.nextInt();
		}
		System.out.print(solution(arr,n,k));
//		for(int x: solution(arr1,arr2,n,m)) {
//			System.out.print(x+" ");
//		}
	}
	public static int solution(int[] arr,int n, int k) {
		int answer=0;
		int gap=0;
		for(int i=0;i<=n-k;i++) {
			gap = arr[i]+arr[i+1]+arr[i+2];
			if(answer<gap) {
				answer = gap;
			}
		}
		return answer;
	}
}