php 不同的最右边的位

Posted 2021-05-05

// DDD:
function differentRightmostBit($n, $m) {
  return call_user_func(function($n,$m){
    $na = str_split(strrev(str_pad(decbin($n),32,'0',STR_PAD_LEFT)));
    $ma = str_split(strrev(str_pad(decbin($m),32,'0',STR_PAD_LEFT)));
    for($i = 0; $i <32; $i++){
      if($na[$i] != $ma[$i]){
        return pow(2,$i);
      }
    }
  }, $n,$m); ;
}

function differentRightmostBit($n, $m) {
  return pow(2, strspn(strrev(sprintf('%032b', $n)) ^ strrev(sprintf('%032b', $m)), "\0")) ;
}

function differentRightmostBit($n, $m) {
  return (($n ^$m) &-($n ^$m));
}