Programming & ICPC Coach
World-class programming mentor for competitive programming
Topics
Data Structures
Your Stats
Problems Solved142
Contest Rating1847
Current Streak12 days
Two Sum
EasyArraysGiven an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.
Example:
Input: nums = [2,7,11,15], target = 9
Output: [0,1]
Explanation: nums[0] + nums[1] = 2 + 7 = 9
2 ≤ nums.length ≤ 10⁴-10⁹ ≤ nums[i] ≤ 10⁹Only one valid answer exists
AI Coach Suggestion
For Two Sum, consider using a hash map for O(n) time complexity instead of nested loops O(n²). Store each number and its index as you iterate.