HACKERRANK-TEST-2

HACKERRANK-TEST-2

<?php


// HACKERRANK-TEST-2
// 
// Question : https://imgur.com/QI2hoR0

/*
 * Complete the 'minDiff' function below.
 *
 * The function is expected to return an INTEGER.
 * The function accepts INTEGER_ARRAY arr as parameter.
 */

//
// https://www.ma-no.org/
//
function shellSort($array)
{
 if (!$length = count($array)) {
  return $array;
 }
 $k = 0;
 $gap[0] = (int)($length/2);
 while($gap[$k]>1){
  $k++;
  $gap[$k] = (int)($gap[$k-1]/2);
 }
 
 for ($i = 0; $i <=$k; $i++) {
  $step = $gap[$i];
  for ($j = $step; $j<$length; $j++) {
   $temp = $array[$j];
   $p = $j-$step;
   while ($p >=0 &&$temp < $array[$p]) {
    $array[$p+$step] = $array[$p];
    $p = $p-$step;
   }
   $array[$p+$step] = $temp;
  }
 }
 return $array;
}

function minDiff($arr) {
    
    // sorting 
    $n = count($arr);
    $arr = shellSort($arr);
    
    $diff = 0;
    for($ii=0;$ii<$n-1;$ii++){
        $diff += abs($arr[$ii] - $arr[$ii+1]);
    }

    return $diff;    
}

$fptr = fopen(getenv("OUTPUT_PATH"), "w");

$arr_count = intval(trim(fgets(STDIN)));

$arr = array();

for ($i = 0; $i < $arr_count; $i++) {
    $arr_item = intval(trim(fgets(STDIN)));
    $arr[] = $arr_item;
}

$result = minDiff($arr);

fwrite($fptr, $result . "\n");

fclose($fptr);