I tried to find For a given positive integer Z, check if Z can be written as PQ, where P and Q are positive integers greater than 1. If Z can be written as PQ, return 1, else return 0
I tried lots with online solution,
Check if one integer is an integer power of another
Finding if a number is a power of 2
but it's not what i need , any hint or any tips?
Here's the naive method - try every combination:
function check($z) { for($p = 2; $p < sqrt($z); $p++) { if($z % $p > 0) { continue; } $q = $p; for($i = 1; $q < $z; $i++) { $q *= $p; } if($q == $z) { //print "$z = $p^$i"; return 1; } } return 0; } Similarly, using php's built in log function. But it may not be as accurate (if there are rounding errors, false positives may occur).
function check($z) { for($p = 2; $p < sqrt($z); $p++) { $q = log($z,$p); if($q == round($q)) { return 1; } } return 0; } 