PHP solution for https://www.hackerrank.com/challenges/jumping-on-the-clouds/

jumping-on-the-clouds.php

<?php
$exampleClouds = [0,0,1,0,0,1,0];
    
echo jumpingOnClouds($exampleClouds);

// Assumptions for jumpingOnClouds function:
// 1. Length: 2 <= count($c) <= 100
// 2. Items: $c[$i] === 0 || $c[$i] === 1
// 3. End-values: $c[0] === $c[ count($c) - 1 ] === 0 
function jumpingOnClouds($c) {
    $min = 0;
    if (gettype($c) !== 'array' || !count($c)) {
        return $min;
    }
    
    $len = count($c);
    define("CUMULUS", 0);
    
    // Always advance twice but return once if value is invalid or forbidden
    for ($i = 2; $i <= $len; $i += 2) {
        if (!array_key_exists($i, $c) || $c[$i] !== CUMULUS) {
            $i--;
        }
        $min++;
    }
    
    return $min;
}

?>