Add divide-two-integers solution

Author: imajinyun

src/leetcode/DivideTwoIntegers.php

@@ -0,0 +1,62 @@
+<?php
+
+declare(strict_types=1);
+
+namespace leetcode;
+
+class DivideTwoIntegers
+{
+    public static function divide(int $x, int $y): int
+    {
+        [$max, $min] = [2147483647, -2147483648];
+        if ($x === $y) {
+            return 1;
+        }
+        if ($y === 1) {
+            return $x;
+        }
+        if ($x === 0) {
+            return 0;
+        }
+        if ($x === $min && $y === -1) {
+            return $max;
+        }
+
+        $sign = $x > 0 ^ $y > 0 ? -1 : 1;
+        [$n, $x, $y] = [0, abs($x), abs($y)];
+        while ($x >= $y) {
+            [$t, $i] = [$y, 1];
+            while ($x >= $t) {
+                $x -= $t;
+                $n += $i;
+                $i <<= 1;
+                $t <<= 1;
+            }
+        }
+        if ($sign < 0) {
+            $n = -$n;
+        }
+
+        return min(max($min, $n), $max);
+    }
+
+    public static function divide2(int $x, int $y): int
+    {
+        if ($x === (1 << 31) && $y === -1) {
+            return (1 << 31) - 1;
+        }
+        $n = 0;
+        [$a, $b] = [abs($x), abs($y)];
+        while ($a - $b >= 0) {
+            [$t, $i] = [$b, 1];
+            while ($a - ($t << 1) >= 0) {
+                $t <<= 1;
+                $i <<= 1;
+            }
+            $a -= $t;
+            $n += $i;
+        }
+
+        return ($x > 0) === ($y > 0) ? $n : -$n;
+    }
+}

tests/leetcode/DivideTwoIntegersTest.php

@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace leetcode\tests;
+
+use PHPUnit\Framework\TestCase;
+use leetcode\DivideTwoIntegers;
+
+class DivideTwoIntegersTest extends TestCase
+{
+    public function testDivide(): void
+    {
+        self::assertSame(3, DivideTwoIntegers::divide(10, 3));
+        self::assertSame(-2, DivideTwoIntegers::divide(7, -3));
+        self::assertSame(0, DivideTwoIntegers::divide(0, 1));
+        self::assertSame(1, DivideTwoIntegers::divide(1, 1));
+        self::assertSame(715827882, DivideTwoIntegers::divide(-2147483648, -3));
+    }
+
+    public function testDivide2(): void
+    {
+        self::assertSame(3, DivideTwoIntegers::divide2(10, 3));
+        self::assertSame(-2, DivideTwoIntegers::divide2(7, -3));
+        self::assertSame(0, DivideTwoIntegers::divide2(0, 1));
+        self::assertSame(1, DivideTwoIntegers::divide2(1, 1));
+        self::assertSame(715827882, DivideTwoIntegers::divide2(-2147483648, -3));
+    }
+}