Last updated 4 years ago
Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have exactly one solution, and you may not use the same element twice.
Given nums = [2, 7, 11, 15], target = 9, Because nums[0] + nums[1] = 2 + 7 = 9, return [0, 1]. Input: [3,2,4], 6 Output: [1,2]
var twoSum = function(nums, target) { // BRUTE // for(var i = 0; i <= nums.length - 1; i++){ // for(var j = 1; j <= nums.length - 1; j++){ // if(nums[i] + nums[j] === target){ // return [i, j] // } // } // } // return result; // TWO POINTER // let sortedNums = nums.sort((a, b) => a - b); // let i = 0; // let j = nums.length - 1; // while(i < j){ // let result = nums[i] + nums[j]; // if(result === target){ // return [i, j] // } // if(result > target){ // j--; // } // if(result < target){ // i++; // } // } // return -1; // HASHMAP let available = {}; for (var i = 0; i <= nums.length - 1; i++) { const val = target - nums[i]; //? if (typeof available[val] !== "undefined") { return [available[val], i]; } else { available[nums[i]] = i; } } return -1; };