Update Q1, Q7 answer (#76)

* Update 001_Two_Sum.py
* Update 007_Reverse_Integer.py

Contributed by @LONGNEW

Author: LONGNEW

python/001_Two_Sum.py

@@ -58,9 +58,4 @@ def twoSum(self, nums, target):
                 begin += 1
             else:
                 end -= 1
-
-
-if __name__ == '__main__':
-    # begin
-    s = Solution()
-    print s.twoSum([3, 2, 4], 6)
+                

python/007_Reverse_Integer.py

@@ -1,39 +1,17 @@
 class Solution:
-    # @return an integer
+    def reverse(self, x):
+        # https://leetcode.com/problems/reverse-integer/
+        flag = True if x < 0 else False
+        if flag:
+            x = -x
+        x = str(x)[::-1]
 
-    # def reverse(self, x):
-    #     max_int = 2147483647
-    #     if x == 0:
-    #         return 0
-    #     isPos = True
-    #     if x < 0:
-    #         x *= (-1)
-    #         isPos = False
-    #     ltemp = []
-    #     while x != 0:
-    #         temp = x % 10
-    #         ltemp.append(temp)
-    #         x /= 10
-    #     result = 0
-    #     # the main solution
-    #     for t in ltemp:
-    #         result = result * 10 + t
-    #     if result > max_int:
-    #         result = 0
-    #     if isPos:
-    #         return result
-    #     else:
-    #         return -1 * result
+        if flag:
+            x = "-" + x
 
-    def reverse(self, x):
-        # Note that in Python -1 / 10 = -1
-        res, isPos = 0, 1
-        if x < 0:
-            isPos = -1
-            x = -1 * x
-        while x != 0:
-            res = res * 10 + x % 10
-            if res > 2147483647:
-                return 0
-            x /= 10
-        return res * isPos
+        value = 2 ** 31
+        x = int(x)
+        if -value <= x < value:
+            return x
+        return 0
+