Given array of integers, find the maximal possible sum of some of its k consecutive elements.

Example

For inputArray = [2, 3, 5, 1, 6] and k = 2, the output should be

solution(inputArray, k) = 8.

All possible sums of 2 consecutive elements are:

• 2 + 3 = 5;
• 3 + 5 = 8;
• 5 + 1 = 6;
• 1 + 6 = 7.Thus, the answer is 8.

Input/Output

• [execution time limit] 3 seconds (java)

• [memory limit] 1 GB

• [input] array.integer inputArray

  Array of positive integers.

  Guaranteed constraints:

  3 ≤ inputArray.length ≤ 105,

  1 ≤ inputArray[i] ≤ 1000.

• [input] integer k

  An integer (not greater than the length of inputArray).

  Guaranteed constraints:

  1 ≤ k ≤ inputArray.length.

• [output] integer

  The maximal possible sum.

풀이

int solution(int[] inputArray, int k) {
    int result = Integer.MIN_VALUE;
    
    for (int i = 0; i <= inputArray.length - k; i ++) {
        int sum = 0;
        
        for (int j = i; j < i + k; j ++) {
            sum += inputArray[j];
        }
        
        if (result < sum) result = sum;
    }
    
    return result;
}