Divide Two integers

Author: joshguha

29_divide_two_integers.py

@@ -0,0 +1,45 @@
+# class Solution(object):
+#     def divide(self, dividend, divisor):
+#         """
+#         :type dividend: int
+#         :type divisor: int
+#         :rtype: int
+#         """
+
+import math
+
+class Solution(object):
+    def divide(self, dividend, divisor):
+        if divisor == 0:
+            return MAX_INT
+        if dividend == 0:
+            return 0
+        isPositive = (dividend < 0) == (divisor < 0)
+        m = abs(dividend)
+        n = abs(divisor)
+        # ln and exp
+        res = math.log(m) - math.log(n)
+        res = int(math.exp(res))
+        if isPositive:
+            return min(res, 2147483647)
+        return max(0 - res, -2147483648)
+
+    # def divide(self, dividend, divisor):
+    #     # (dividend >= 0) ^ (divisor < 0)
+    #     isPositive = (dividend < 0) == (divisor < 0)
+    #     dividend, divisor, result = abs(dividend), abs(divisor), 0
+    #     while dividend >= divisor:
+    #         n, nb = 1, divisor
+    #         # fast minus
+    #         while dividend >= nb:
+    #             dividend, result = dividend - nb, result + n
+    #             n, nb = n << 1, nb << 1
+    #     if isPositive:
+    #         return min(result, 2147483647)
+    #     return max(-result, -2147483648)
+
+if __name__ == '__main__':
+    s = Solution()
+    print s.divide(1, 1)
+
+