<?php $N = trim(fgets(STDIN)); $points = explode(' ', trim(fgets(STDIN))); sort($points); $min = PHP_INT_MAX; for($i = 0, $c = count($points); $i < $c - 1; $i++) { if (($diff = $points[$i+1] - $points[$i]) > 0) { $min = min($min, $diff); } } if ($min == PHP_INT_MAX || $min == 0) { echo "0\n"; } else { echo "$min\n"; }