Merge pull request #121 from Vrindagupta6828/vrinda-patch2

Added Two Sum Problem in interview Questions

Interview_questions/Two_Sum.py

@@ -0,0 +1,46 @@
+"""
+Question:
+    
+Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.
+
+You may assume that each input would have exactly one solution, and you may not use the same element twice.
+
+You can return the answer in any order.
+
+ 
+
+Example 1:
+
+Input: nums = [2,7,11,15], target = 9
+Output: [0,1]
+Output: Because nums[0] + nums[1] == 9, we return [0, 1].
+Example 2:
+
+Input: nums = [3,2,4], target = 6
+Output: [1,2]
+Example 3:
+
+Input: nums = [3,3], target = 6
+Output: [0,1]
+ 
+
+Constraints:
+
+2 <= nums.length <= 105
+-109 <= nums[i] <= 109
+-109 <= target <= 109
+Only one valid answer exists.  """
+
+from typing import List
+import collections
+def twoSum(nums: List[int], target: int) -> List[int]:
+        dicto=collections.defaultdict(int)
+        for i,num in enumerate(nums):
+            cc=target - nums[i]
+            if cc in dicto:
+                return [dicto[cc],i]
+
+            dicto[num]=i
+twoSum([2,7,11,15],9)
+
+#OUTPUT: [0, 1]