Longest Run

longestrun.php

<?php
class Run
{
    public static function indexOfLongestRun($str)
    {
        
    $strlen = strlen( $str );
    $strlen=$strlen-1;
    
    $maxIndex = 0;
    $maxLength = 1;
    $currentChar = $str[0];
    $currentIndex = 0;
    $currentLength = 1;
    
    for( $i = 0; $i <= $strlen; $i++ ) { 
        $sub = $i - 1;
        $currentChar = substr( $str, $sub, 1 ); 
        
            if ($str[$i] == $currentChar) { 
                $currentLength++;            
            } else {
                if ($maxLength < $currentLength) {
                    $maxIndex = $currentIndex;
                    $maxLength = $currentLength;
                }
                $currentLength = 1;
                $currentIndex = $i;
                $currentChar = $str[$i];
                    
            }
        
    }
            if ($maxLength < $currentLength)
                $maxIndex = $currentIndex;
                
            return $maxIndex; 
        
    }
}


// For testing purposes (do not submit uncommented):
/*
echo Run::indexOfLongestRun('abbcccddddcccbba');
*/