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] Output: 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]
Constraints:
2 <= nums.length <= 105
-109 <= nums[i] <= 109
-109 <= target <= 109
- Only one valid answer exists.
Solution(javascript)
const twoSum = (nums, target) => {
const memo = {}
const aux = (index) => {
if (memo[nums[index]] !== undefined) {
return [memo[nums[index]], index]
}
memo[target - nums[index]] = index
return aux(index + 1)
}
return aux(0, nums.length - 1)
}