26. 两数相除

<?php
class Solution {
    public function divide1($dividend, $divisor) {
        $sign = 1;
        if (($dividend < 0 && $divisor > 0) || ($dividend > 0 && $divisor < 0)) {
            $sign = -1;
        }
        $newDividend = abs($dividend);
        $newDivisor = abs($divisor);
        if ($newDividend < $newDivisor) return 0;
        $sum = $newDivisor;
        $multi = 1;
        while($sum + $sum < $newDividend) {
            $sum += $sum;
            $multi += $multi;
        }
        $data = $multi + $this->divide1($newDividend - $sum, $newDivisor);
        $num = $sign < 1 ? 0 - $data : $data;
        if ($num > pow(2, 31) - 1) return pow(2, 31) - 1;
        if ($num > pow(2, 31)) return pow(-2, 31);
        return $num;
    }
    public function divide2($dd, $dr) {
        $sign = 1;
        if (($dd < 0 && $dr > 0) || ($dd > 0 && $dr < 0)) {
            $sign = -1;
        }
        $dd = abs($dd);
        $dr = abs($dr);
        $multi = 0;
        while ($dd - $dr > 0) {
            $dd = $dd - $dr;
            $multi++;
        }
        return [$multi, $dd];
    }
}
$cls = new Solution();
$r = $cls->divide1(10, 3);
print_r($r);