Leetcode PHP题解--D49 821. Shortest Distance to a Character

<?php

class Solution {

    function shortestToChar($S, $C) {

        $S = str_split($S);

        $keys = array_keys($S,$C);

        $distances = [];

        $prev = 0;

        foreach($S as $index => $char){

            $dist = abs($keys[$prev] - $index);

            if($index > $keys[$prev] && isset($keys[$prev+1])){

                $dist = min($index-$keys[$prev],$keys[$prev+1]-$index);

                if($dist == 0){

                    $prev++;

                }

            }

            $distances[] = $dist;

        }

​

        return $distances;

    }

}