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Daily Coding Challenge

Streak: 5 days

EASYTwo Sum

Success Rate: 47%

Two Sum

Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.

You may assume that each input would have exactly one solution, and you may not use the same element twice.

Example 1:

Input: nums = [2,7,11,15], target = 9

Output: [0,1]

Explanation: Because nums[0] + nums[1] == 9, we return [0, 1].

Constraints:

2 ≤ nums.length ≤ 10⁴
-10⁹ ≤ nums[i] ≤ 10⁹
-10⁹ ≤ target ≤ 10⁹
Only one valid answer exists.

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Solution.js

function twoSum(nums, target) {
  const map = new Map();

  for (let i = 0; i < nums.length; i++) {
    const complement = target - nums[i];

    if (map.has(complement)) {
      return [complement, nums[i]];
    }

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

  return [];
}

// Test case
const nums = [3, 2, 4];
const target = 6;
console.log(twoSum(nums, target)); // Expected: [1, 2]

function twoSum(nums, target) {
  const map = new Map();

  for (let i = 0; i < nums.length; i++) {
    const complement = target - nums[i];

    if (map.has(complement)) {
      return [complement, nums[i]];
    }

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

  return [];
}

// Test case
const nums = [3, 2, 4];
const target = 6;
console.log(twoSum(nums, target)); // Expected: [1, 2]

Console Output

Click "Run" to see output...

Test Cases

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Test Case 1: nums = [3,2,4], target = 6

Not run

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Test Case 2: nums = [2,7,11,15], target = 9

Locked

-

Test Case 3: nums = [3,3], target = 6

Locked