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 pai...
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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) Line 1 class Solution:
