Solving Two Sum II (Sorted Array) Using the Two Pointer Technique in Python

Introduction In this problem, we need to find two numbers that add up to a given target. Since the array is already sorted, we can use a more efficient approach instead of checking all possible pairs. Problem Explanation You are given: A sorted array of integers ( numbers ) A target value Find two numbers such that their sum equals the target and return their indices using 1-based indexing. Example Input: numbers = [2, 7, 11, 15], target = 9 Output: [1, 2] Because 2 + 7 = 9 Approach Used – Two Pointer Technique Use two pointers: left at the beginning right at the end Move the pointers based on the sum until the target is found. Code (Python) class Solution : def twoSum ( self , numbers : list [ int ], target : int ) -> list [ int ]: left = 0 right = len ( numbers ) - 1 while left < right : current_sum = numbers [ left ] + numbers [ right ] if current_sum == target : return [ left + 1 , right + 1 ] elif current_sum < target : left += 1 else : right -= 1 Code Explanation (Step by Step) L