Added python code for 189. Rotate Array & 137. Single Number II (#98)

* Create Rotate-List.py and update README

* minor fix of the link

* Added 137. Single Number II

Co-authored-by: Gourav Rusiya <[email protected]>

Author: jameszu

Python/rotate-array.py

@@ -0,0 +1,12 @@
+class Solution:
+    def rotate(self, nums: List[int], k: int) -> None:
+        """
+        Do not return anything, modify nums in-place instead.
+        """
+        lenz = len(nums)
+        k = k % lenz
+        if k == 0:
+            return nums
+        nums += nums[:-k]
+        del nums[:lenz-k]
+        

Python/single-number-ii.py

@@ -0,0 +1,22 @@
+class Solution:
+    def singleNumber(self, nums: List[int]) -> int:
+        dict1 = {} # Create hashtable
+        # Add counts into the hashtable
+        for x in nums:
+            if x not in dict1:
+                dict1[x] = 1
+            else:
+                dict1[x] += 1
+        # Select the single element
+        for ans, y in dict1.items():
+            if y == 1:
+                return ans
+
+# Or bitwise way
+class Solution:
+    def singleNumber(self, nums: List[int]) -> int:        
+        a, b = 0, 0
+        # Just bitwise operation, (notx and a and notb) or (x and nota and b) ... 
+        for x in nums:
+            a, b = (~x&a&~b)|(x&~a&b), ~a&(x^b)
+        return b

README.md

@@ -83,10 +83,12 @@ Check out ---> [Sample PR](https://github.com/codedecks-in/LeetCode-Solutions/pu
 | #    | Title                                                                 | Solution                                                                                                       | Time   | Space  | Difficulty | Tag | Tutorial                                 |
 | ---- | --------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------- | ------ | ------ | ---------- | --- | ---------------------------------------- |
 | 0136 | [Single Number](https://leetcode.com/problems/single-number/)         | [Java](./Java/single-number.java) <br> [Python](./Python/single-number.py) <br> [C++](./C++/Single-Number.cpp) | _O(n)_ | _O(1)_ | Easy       |     | Using XOR                                |
+| 137  | [Single Number II](https://leetcode.com/problems/single-number-ii/)   | [Python](./Python/single-number-ii.py)                                                                           | _O(n)_ | _O(1)_ | Medium       |     |                                          |
 | 260  | [Single Number III](https://leetcode.com/problems/single-number-iii/) | [Python](./Python/single-number-iii.py)                                                                        | _O(n)_ | _O(1)_ | Medium     |     |                                          |
 | 476  | [Number Complement](https://leetcode.com/problems/number-complement/) | [Java](./Java/number-complement.java)                                                                          | _O(1)_ | _O(1)_ | Easy       |     | [Tutorial](https://youtu.be/6bp5V-O3zts) |
 | 520  | [Detect Capital Use](https://leetcode.com/problems/detect-capital/)   | [Python](./Python/detect-capital.py)                                                                           | _O(n)_ | _O(1)_ | Easy       |     |                                          |
 
+
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     <b><a href="#algorithms">⬆️ Back to Top</a></b>
@@ -119,6 +121,7 @@ Check out ---> [Sample PR](https://github.com/codedecks-in/LeetCode-Solutions/pu
 | 152     | [Maximum Product Subarray](https://leetcode.com/problems/maximum-product-subarray/)                                           | [Javascript](./JavaScript/152.Maximum-Product-Subarray.js)                                                        | O(n)         | O(n)          | Medium     | Array              |
 | 073     | [Set-Matrix-Zeroes](https://leetcode.com/problems/set-matrix-zeroes/)                                                         | [Java](./Java/set-matrix-zeroes.java)                                                                             | O(MN)        | O(1)          | Medium     | Array              |
 | 1288   | [Remove-Covered-Intervals](https://leetcode.com/problems/remove-covered-intervals)                      | [C++](./C++/Remove-Covered-Intervals.cpp)                                                      | O(N*N)        | O(1)          | Medium     | Array              |
+| 189     | [Rotate-Array](https://leetcode.com/problems/rotate-array/)                                                         | [Python](./Python/rotate-array.py)                                                                             | O(N)        | O(1)          | Medium     | Array 
 
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@@ -414,6 +417,7 @@ DISCLAIMER: This above mentioned resources have affiliate links, which means if
 | [Jaseem ck](https://github.com/Jaseemck) <br> <img src="https://github.com/Optider.png" width="100" height="100">                                                                               | India   | Python               | [Github](https://github.com/Jaseemck)                                                                                                                                                                                       |
 | [Ilias Khan](https://github.com/IliasKhan) <br> <img src="https://avatars3.githubusercontent.com/u/26863936?s=460&u=4501ffba5efd1a7b978416e8e434dff599c85384&v=4" width="100" height="100"> | India   | C++                  | [codechef](https://www.codechef.com/users/iliaskhan) <br> [Hackerrank](ckerrank.com/iliaskhan57) <br> [LeetCode](https://leetcode.com/ilias_khan/) <br> [codeforces](http://codeforces.com/profile/iliaskhan) |
 | [Shamoyeeta Saha](https://github.com/Shamoyeeta) <br> <img src="https://i.pinimg.com/236x/dc/ef/3a/dcef3abedf0e0761203aaeb85886a6f3--jedi-knight-open-source.jpg" width="100" height="100"> | India     | C++                  | [Hackerrank](https://www.hackerrank.com/sahashamoyeeta) <br> [Github](https://github.com/Shamoyeeta) |
+| [James Y](https://github.com/jameszu) <br> <img src="https://avatars0.githubusercontent.com/u/41566813?s=400&u=af77d15517566ea590a316030b4a6d402b0041b6&v=4" width="100" height="100"> | New Zealand     | python                  | [Github](https://github.com/jameszu) |
 
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