Arrays & Hashing/Easy

Two SumFREE TRACK

Time: O(N)Space: O(N)

Target is 9. We iterate through nums array and maintain a hash map of { value: index }.

Array Elements & Pointers

i=0

i=1

i=2

i=3

Live Variables & Invariants

target:9

i:0

current:-

complement:-

Step 1 / 520%

Solution Code

function twoSum(nums: number[], target: number): number[] {

  const map = new Map<number, number>();

  for (let i = 0; i < nums.length; i++) {

    const complement = target - nums[i];

    if (map.has(complement)) return [map.get(complement)!, i];

    map.set(nums[i], i);

  return [];

Input your custom values and visualize step-by-step trace

Array Input (comma separated):

Target Number:

Quick Presets:

Contextual Tutor for Two Sum

Hello! I am your AI DSA Tutor for **Two Sum** (Arrays & Hashing). Ask me anything about this algorithm, time complexity, or request a step hint!