added solutions for 217; updated Readme; improved coding style for 167

Author: Dominik Schauer

README.md

@@ -1,3 +1,7 @@
-Here I brag about how accomplished and productive I am by dumping my working LeetCode solutions. Since no one can see the failed attempts I look supersmart. Nevermind my profile.
+Here I brag about how accomplished and productive I am by dumping my working LeetCode solutions. Since no one can see the failed attempts I look supersmart to potential employers.
 
+My profile: 
 https://leetcode.com/user6659P/
+
+Helpful guideline for starting with LeetCode: 
+https://seanprashad.com/leetcode-patterns/

algorithms/15_3Sum.py

@@ -0,0 +1,3 @@
+class Solution:
+    def threeSum(self, nums: List[int]) -> List[List[int]]:
+        

algorithms/167_two_sum_ii_input_array_is_sorted.py

@@ -20,8 +20,8 @@ def twoSum(self, numbers: List[int], target: int) -> List[int]:
         while True: 
             current_sum = numbers[left] + numbers[right]
             if(current_sum == target):
-                return((left+1, right+1));
+                return((left+1, right+1))
             elif(current_sum < target):
-                left += 1;
+                left += 1
             else:
-                right -= 1;
+                right -= 1

algorithms/217_contains_duplicate_hash_table.py

@@ -0,0 +1,19 @@
+# By using a dictionary to remember each value we had seen before, 
+# we will know in case we encounter the same value a second time (i.e. it's a duplciate)
+# Obviously there's no need to go this far if there aren't at least two
+# values in the array, since then it's impossible to have duplicates. 
+
+class Solution:
+    def containsDuplicate(self, nums: List[int]) -> bool:
+        if(len(nums) < 2):
+            return False
+        
+        value_dict = {}
+        
+        for i in range(0,len(nums)):
+            if(nums[i] in value_dict):
+                return True
+            else:
+                value_dict[nums[i]] = None
+            
+        return False

algorithms/217_contains_duplicate_sorting.py

@@ -0,0 +1,17 @@
+# By sorting the array we can subsequently check if two adjacent numbers
+# in it have the same value (i.e. if they are duplicates)
+# Obviously there's no need to go this far if there aren't at least two
+# values in the array, since then it's impossible to have duplicates. 
+
+class Solution:
+    def containsDuplicate(self, nums: List[int]) -> bool:
+        if(len(nums) < 2):
+            return False
+        else:
+            nums.sort()
+        
+        for i in range(0,len(nums)-1):
+            if(nums[i] == nums[i+1]):
+                return True
+            
+        return False