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  1. Queues: A Tale of Two Stacks
  2. Discussions

Queues: A Tale of Two Stacks

  • vaisakhkolathara
     + 0 comments

    Solution in PHP

    <?php
$_fp = fopen("php://stdin", "r");
/* Enter your code here. Read input from STDIN. Print output to STDOUT */

$q = intval(trim(fgets(STDIN)));
$array = [];
for ($t_itr = 0; $t_itr < $q; $t_itr++) {
    $s = rtrim(fgets(STDIN), "\r\n");
    $arr = array_map('intval', preg_split('/ /', $s, -1, PREG_SPLIT_NO_EMPTY));
    if ($arr[0] == 1 && !empty($arr[1])) {
        array_unshift($array, $arr[1]);
    } elseif ($arr[0] == 2) {
        array_pop($array);
    } elseif ($arr[0] == 3) {
        echo $array[count($array)- 1] . PHP_EOL;
    }
}
fclose($_fp);
?>