Divide Players Into Teams of Equal Skill
You are given a positive integer array skill of even length n where skill[i] denotes the skill of the i^th player. Divide the players into n / 2 teams of size 2 such that the total skill of each team is equal.
The chemistry of a team is equal to the product of the skills of the players on that team.
Return the sum of the chemistry of all the teams, or return -1 if there is no way to divide the players into teams such that the total skill of each team is equal.
Example 1
Input
skill = [3,2,5,1,3,4]Output
22Teams can be formed as (1, 5), (2, 4), and (3, 3), each with total skill 6, and their chemistry sum is 22.
Example 2
Input
skill = [3,4]Output
12The two players form one team with chemistry 3 * 4 = 12.
Constraints
- 2 <= skill.length <= 10^5
- skill.length is even.
- 1 <= skill[i] <= 1000