643. Maximum Average Subarray I

Description

You are given an integer array nums consisting of n elements, and an integer k.

Find a contiguous subarray whose length is equal to k that has the maximum average value and return this value. Any answer with a calculation error less than 10-5 will be accepted.

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최대평균값을 갖는 k길이의 부분연속배열 찾아 반환합니다. 반환합니다. 계산오류가 10-5보다 작은 답은 모두 허용됩니다.

Example 1:

Input: nums = [1,12,-5,-6,50,3], k = 4
Output: 12.75000
Explanation: 최대평균갑은 (12 - 5 - 6 + 50) / 4 = 51 / 4 = 12.75

Example 2:

Input: nums = [5], k = 1
Output: 5.00000

Constraints:

• n == nums.length
• 1 <= k <= n <= 105
• -104 <= nums[i] <= 104

Soluion

class Solution {
    public double findMaxAverage(int[] nums, int k) {
        double sum = 0;
        for (int i = 0; i < k; i++) {
            sum += nums[i];
        }
        double avg = sum / k;
        double maxAvg = avg;

        for (int i = k; i < nums.length; i++) {
            sum = sum - nums[i - k] + nums[i];
            avg = sum / k;
            maxAvg = Math.max(maxAvg, avg);
        }

        return maxAvg;
    }
}