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Sergio Alves
Algorithms, Leetcode 75, PHP

Leetcode 75 – 643. Maximum Average Subarray I

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.

Example 1:

Input: nums = [1,12,-5,-6,50,3], k = 4
Output: 12.75000
Explanation: Maximum average is (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

PHP Code

class Solution {

    /**
     * @param Integer[] $nums
     * @param Integer $k
     * @return Float
     */
    function findMaxAverage($nums, $k) {
        $result = -2147483648;
        $j = $k-1;
        for ($i=0; $i<count($nums)-$k+1; $i++) {
            $sum = $nums[$i];
            while ($j > 0) {
                $sum += $nums[$i+$j];
                $j--;
            }
            if ($sum > $result) {
                $result = $sum;
            }
            $j = $k-1;
        }
        return $result / $k;
    }
}