Two Sum II - Input Array Is Sorted-java(LEETCODE:167)

Solving Two Sum II in Java Using Two Pointers (Sorted Array Approach) Introduction After understanding the standard Two Sum problem using hashing, I came across a variation: Two Sum II – Input Array Is Sorted At first glance, it looks similar, but the key difference is: The array is already sorted. This small detail allows us to use a more optimal and space-efficient approach. Problem Statement Given a 1-indexed sorted array of integers, find two numbers such that they add up to a specific target. Constraints: Exactly one solution exists You may not use the same element twice The solution must use constant extra space Key Observation Since the array is sorted: Smaller numbers are on the left Larger numbers are on the right This allows us to avoid extra space and use a two-pointer technique . My Thought Process Instead of storing values like in HashMap, I asked: “Can I use the sorted property to move intelligently?” So I placed: One pointer at the start One pointer at the end Two Pointe