TwoSum

Author: Shikha-code36

Arrays/001-twosum.py

@@ -0,0 +1,34 @@
+'''Leetcode - https://leetcode.com/problems/two-sum/ '''
+'''
+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.
+
+Input: nums = [2,7,11,15], target = 9
+Output: [0,1]
+'''
+
+# Solution1
+def twoSum(nums, target):
+    for i in range(len(nums)):
+        for j in range(i+1, len(nums)):
+            if nums[i] + nums[j] == target:
+                return [i, j]
+# T:O(N^2)
+# S:O(1)
+
+# Solution2 
+def twoSum(nums, target):
+    dict = {}
+    for i in range(len(nums)):
+        diff = target - nums[i]
+        if diff in dict:
+            return [dict[diff], i]
+        dict[nums[i]] = i
+
+# T: O(N)
+# S: O(N)
+
+

README.md

@@ -29,6 +29,7 @@ Check the notes for the explaination - [Notes](https://stingy-shallot-4ea.notion
     - [x] [Counting Bits](Dynamic-Programming/338-Counting-Bits.py)
 
 - [x] [Arrays](Arrays)
+    - [x] [Two Sum](Arrays/001-twosum.py)
     - [x] [Contains Duplicate](Arrays/217-Contains-duplicate.py)
     - [x] [Product Of Array Except Self](Arrays/238-product-of-array-except-self.py)