Leetcode - Two Sum

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]

Solution,#

1. 먼저 모두 순회시켜서 Map 에 넣는다
2. 다시 순회하면서 계산해본다

class Solution {
    fun twoSum(nums: IntArray, target: Int): IntArray {
        val temp = mutableMapOf<Int, Int>();
        for ((i, v) in nums.withIndex()) {
            temp.put(v, i);
        }
        for ((i, v) in nums.withIndex()) {
            if (temp.contains(target - v) && temp.get(target - v)!! != i) {
                return intArrayOf(temp.get(target - v)!!, i)
            }
        }
        
        return intArrayOf()
    }
}