scramble.php

<?php
// 7 kyu - String Scramble
// Given a string and an array of index numbers, return the characters of the string rearranged to be in the order specified by the accompanying array.
//
// Ex:
//
// scramble('abcd', [0,3,1,2]) -> 'acdb'
//
// The string that you will be returning back will have: 'a' at index 0, 'b' at index 3, 'c' at index 1, 'd' at index 2, because the order of those characters maps to their corisponding numbers in the index array.
//
// In other words, put the first character in the string at the index described by the first element of the array
//
// You can assume that you will be given a string and array of equal length and both containing valid characters (A-Z, a-z, or 0-9).

function scramble($str,$arr){
  foreach($arr as $key => $val) {
    $result[$val] = $str[$key];
  }
  ksort($result);
  return implode($result);
}

// Alternative Solutions:
// function scramble($str, $arr) {
//   $newStr = $str;
//   for ($i = 0; $i < strlen($str); $i++) {
//     $newStr[$arr[$i]] = $str[$i];
//   }
//   return $newStr;
// }

// function scramble($str,$arr){
//  $a = array_combine($arr,str_split($str));
//  ksort($a);
//  return implode('', $a);
// }

?>