add some solutions

Author: Jack

Python/single-number-ii.py

@@ -5,9 +5,10 @@
 # 
 # Note:
 # Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?
-#
+import collections
 
-class Solution:
+
+class Solution(object):
     # @param A, a list of integer
     # @return an integer
     def singleNumber(self, A):
@@ -16,7 +17,7 @@ def singleNumber(self, A):
             one, two = (~x & one) | (x & ~one & ~two), (~x & two) | (x & one)
         return one
 
-class Solution2:
+class Solution2(object):
     # @param A, a list of integer
     # @return an integer
     def singleNumber(self, A):
@@ -29,8 +30,27 @@ def singleNumber(self, A):
             two &= ~carry
         return one
 
+
+class Solution3(object):
+    def singleNumber(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: int
+        """
+        return (collections.Counter(list(set(nums)) * 3) - collections.Counter(nums)).keys()[0]
+
+
+class Solution4(object):
+    def singleNumber(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: int
+        """
+        return (sum(set(nums)) * 3 - sum(nums)) / 2
+
+
 #  every element appears 4 times except for one with 2 times
-class SolutionEX:
+class SolutionEX(object):
     # @param A, a list of integer
     # @return an integer
     # [1, 1, 1, 1, 2, 2, 2, 2, 3, 3]

Python/single-number-iii.py

@@ -14,7 +14,9 @@
 # above example, [5, 3] is also correct.
 # Your algorithm should run in linear runtime complexity.
 # Could you implement it using only constant space complexity?
-#
+import operator
+import collections
+
 
 class Solution:
     # @param {integer[]} nums
@@ -26,7 +28,8 @@ def singleNumber(self, nums):
         for i in nums:
             result[bool(i & bit)] ^= i
         return result
-        
+
+
 class Solution2:
     # @param {integer[]} nums
     # @return {integer[]}
@@ -43,3 +46,12 @@ def singleNumber(self, nums):
                 x ^= i
 
         return [x, x ^ x_xor_y]
+
+
+class Solution3(object):
+    def singleNumber(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: List[int]
+        """
+        return [x[0] for x in sorted(collections.Counter(nums).items(), key=lambda i: i[1], reverse=False)[:2]]

Shell/valid-phone-numbers.sh

@@ -1,3 +1,4 @@
+#!/usr/bin/env bash
 # Time:  O(n)
 # Space: O(1)
 #