Minimum Index Sum of Two Lists Algorithm Javascript

Suppose Andy and Doris want to choose a restaurant for dinner, and they both have a list of favorite restaurants represented by unique strings.

You need to help them find out their common interest with the least list index sum. If there is a choice tie between answers, output all of them in alphabetical order. 

You could assume there always exists an answer.

Example 1:

Input: list1 = [Shogun, Tapioca Express, Burger King, KFC] , list2 = [Piatti, The Grill at Torrey Pines, Hungry Hunter Steakhouse, Shogun]

Output: [Shogun]

Explanation: The only restaurant they both like is "Shogun".

Example 2:

Input: list1 = [Shogun, Tapioca Express, Burger King, KFC] , list2 = [KFC, Shogun, Burger King]

Output: [Shogun]

Explanation: The restaurant they both like and have the least index sum is "Shogun" with index sun 1 (0+1).

Example 3:

Input: listi = [Shogun, Tapioca Express, Burger King, KFC] , list2 = [KFC,Burger King, Tapioca Express, Shogun]

Output: [ Burger King, KFC, Shogun, Tapioca Express]

Example 4:

Input: list1 = [Shogun, Tapioca Express, Burger King, KFC] , list2 = [KNN, KFC, Burger King, Tapioca Express, Shogun]

Output: [ Burger King, KFC, Shogun, Tapioca Express]

Example 5:

Input: list1 = [KFC], list2 = [KFC]

Output: [KFC]