3. 최대 매출

import java.util.*;

class Main {
	public int solution(int[] input, int N) {
		int answer = 0;
		int index = 0;
		int max = Integer.MIN_VALUE;
		while (index <= input.length - N) {
			int sum = 0;
			for (int i = 0; i < N; i++) {
				sum += input[index + i];
			}
			max = Math.max(max, sum);
			index++;
		}
		answer = max;
		return answer;
	}

	public static void main(String[] args) {
		Main T = new Main();
		Scanner kb = new Scanner(System.in);
		int M = kb.nextInt();
		int N = kb.nextInt();
		int[] input = new int[M];
		for (int i = 0; i < M; i++)
			input[i] = kb.nextInt();
		System.out.print(T.solution(input, N));
		kb.close();
	}

}

4번째 테스트 케이스 시간 초과

 

import java.util.*;

class Main {
	public int solution(int[] input, int N) {
		int answer = 0;
		int index = 0;
		int sum = 0;
		for (int i = 0; i < N; i++) {
			sum += input[i];
		}
		int max = sum;
		while (index < input.length - N) {
			sum = sum - input[index] + input[index + N];
			max = Math.max(max, sum);
			index++;
		}
		answer = max;
		return answer;
	}

	public static void main(String[] args) {
		Main T = new Main();
		Scanner kb = new Scanner(System.in);
		int M = kb.nextInt();
		int N = kb.nextInt();
		int[] input = new int[M];
		for (int i = 0; i < M; i++)
			input[i] = kb.nextInt();
		System.out.print(T.solution(input, N));
		kb.close();
	}

}