Leetcode - 1. Two Sum

Using Hashmap (Optimal solution)

/**
 * @param {number[]} nums
 * @param {number} target
 * @return {number[]}
 */
var twoSum = function (nums, target) {
    let myMap = new Map();

    for (let i = 0; i < nums.length; i++) {
        myMap.set(nums[i], i);
    }
    for (let i = 0; i < nums.length; i++) {
        let remaining = target - nums[i];
        if (myMap.has(remaining) && myMap.get(remaining) !== i) {
            return [i, myMap.get(remaining)];
        }
    }
};

Using Pointers

/**
 * @param {number[]} nums
 * @param {number} target
 * @return {number[]}
 */
var twoSum = function(nums, target) {

   let left = 0;
   let right = 1


   while(left <= nums.length-1){

       if(nums[left] + nums[right] === target){
           return [left,right]
       }else if (right === nums.length-1){
           left++;
           right = left+1;
       }
       else{
           right++;
       }
   }
};