solution_1.go

// package solution1 for the problem https://leetcode.com/problems/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]
//
// Constraints:
//     2 <= nums.length <= 104
//     -109 <= nums[i] <= 109
//     -109 <= target <= 109
//     Only one valid answer exists.
//
// Follow-up: Can you come up with an algorithm that is less than O(n2) time complexity?
package solution1

// twoSum return indices of the two numbers such that they add up to target.
func twoSum(nums []int, target int) []int {
	for i, v := range nums {
		for a, av := range nums {
			if i == a {
				continue
			}
			if v+av == target {
				return []int{i, a}
			}
		}
	}
	return []int{}
}