Sergio Alves

Given a binary array nums and an integer k, return the maximum number of consecutive 1‘s in the array if you can flip at most k 0‘s.

Example 1:

Input: nums = [1,1,1,0,0,0,1,1,1,1,0], k = 2
Output: 6
Explanation: [1,1,1,0,0,1,1,1,1,1,1]
Bolded numbers were flipped from 0 to 1. The longest subarray is underlined.

Example 2:

Input: nums = [0,0,1,1,0,0,1,1,1,0,1,1,0,0,0,1,1,1,1], k = 3
Output: 10
Explanation: [0,0,1,1,1,1,1,1,1,1,1,1,0,0,0,1,1,1,1]
Bolded numbers were flipped from 0 to 1. The longest subarray is underlined.

Constraints:

• 1 <= nums.length <= 105
• nums[i] is either 0 or 1.
• 0 <= k <= nums.length

PHP Code

class Solution {

    /**
     * @param String $s
     * @param Integer $k
     * @return Integer
     */
    function maxVowels($s, $k) {
        $s_array = str_split($s);
        $sum = 0;
        for ($i=0; $i<$k; $i++) {
            if (preg_match("/[aeiou]/i", $s_array[$i])) {
                $sum++;
            }
        }
        $result = $sum;
        
        for ($i=$k; $i<count($s_array); $i++) {
            if (preg_match("/[aeiou]/i", $s_array[$i])) {
                $sum++;
            }
            if (preg_match("/[aeiou]/i", $s_array[$i-$k])) {
                $sum--;
            }         
            if ($sum > $result) {
                $result = $sum;
            }
        }
        return $result;
    }
}