LC 1 Two Sum

Implementation

// 1. Two Sum
// https://leetcode.com/problems/two-sum/description/
// 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.

// You can return the answer in any order.
// Example 1:
// Input: nums = [2,7,11,15], target = 9
// Output: [0,1]
// Explanation: Because nums[0] + nums[1] == 9, we return [0, 1].

// Example 2:
// Input: nums = [3,2,4], target = 6
// Output: [1,2]

// Example 3:
// Input: nums = [3,3], target = 6
// Output: [0,1]

const twoSum = (nums, target) => {
    const indexByValue = new Map();
    for(let i=0;i<nums.length;i++){
        let currentNum = nums[i];
        let targetNum = target-currentNum;
        if(indexByValue.has(targetNum)){
            return [i,indexByValue.get(targetNum)]
        }
        indexByValue.set(currentNum,i);
    }
};

console.log(twoSum([2,7,11,15],9));
console.log(twoSum([3,2,4],6));
console.log(twoSum([3,3],6));

Tests

// Test stub for 01.TwoSum

describe('01.TwoSum', () => {
  it('should have a test stub', () => {
    expect(true).toBe(true);
  });
});