<?php
function isPerfect($n) {
return count($n)==4&&$n[0]*$n[1]*$n[2]*$n[3]+1==pow(pow($n[0],2)+3*$n[0]+1,2);
}
var_dump(isPerfect([1,2,3,4]));
var_dump(isPerfect(['1','2','3','4']));
var_dump(isPerfect([3,9,5,6]));
var_dump(isPerfect([1,2,3,4,5]));
var_dump(isPerfect(['a','b','c','d']));
var_dump(isPerfect([1,'b',3,4]));
var_dump(isPerfect([1001,1002,1003,1004]));
preferences:
46.48 ms | 402 KiB | 5 Q