Two Sum
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.
Example:
Given nums = [2, 7, 11, 15], target = 9,
Because nums[0] + nums[1] = 2 + 7 = 9,
return [0, 1].
Solution
/**
* @param {number[]} nums
* @param {number} target
* @return {number[]}
*/
var twoSum = function(nums, target) {
for (let i = 0 ; i < nums.length; i++) {
let s = nums.findIndex((e, index) => {
if (e === (target - nums[i])) {
if (i === index) return false
return true
}
return false
})
if (s > -1) return [i, s]
}
return []
}/**
* @param {number[]} nums
* @param {number} target
* @return {number[]}
*/
var twoSum = function(nums, target) {
let obj = {}
nums.map((num, index) => (obj[num] = index))
for (let i = 0; i < nums.length; i++) {
let second = target - nums[i]
if (obj.hasOwnProperty(second) && (obj[second] !== i)) {
return [i ,obj[second]]
}
}
return []
}/**
* @param {number[]} nums
* @param {number} target
* @return {number[]}
*/
var twoSum = function(nums, target) {
let obj = {}
for (let i = 0; i < nums.length; i++) {
let num = nums[i]
let second = target - num
if (obj.hasOwnProperty(second)) {
return [obj[second], i]
}
obj[num] = i
}
return []
}