#python3
'''
Suppose Andy and Doris want to choose a restaurant for dinner, and they both have a list of favorite restaurants represented by 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 with no order requirement. You could assume there always exists an answer.

Example 1:
Input:
["Shogun", "Tapioca Express", "Burger King", "KFC"]
["Piatti", "The Grill at Torrey Pines", "Hungry Hunter Steakhouse", "Shogun"]
Output: ["Shogun"]
Explanation: The only restaurant they both like is "Shogun".
Example 2:
Input:
["Shogun", "Tapioca Express", "Burger King", "KFC"]
["KFC", "Shogun", "Burger King"]
Output: ["Shogun"]
Explanation: The restaurant they both like and have the least index sum is "Shogun" with index sum 1 (0+1).
Note:
The length of both lists will be in the range of [1, 1000].
The length of strings in both lists will be in the range of [1, 30].
The index is starting from 0 to the list length minus 1.
No duplicates in both lists.
'''
def findRestaurant(list1, list2):
	commonRestaurants = set(list1) & set(list2)
	if len(commonRestaurants) == 1:
		return list(commonRestaurants)
	else:
		commonRestaurantsDict = {}
		for commonRestaurant in commonRestaurants:
			commonRestaurantsDict[commonRestaurant] = list1.index(commonRestaurant) + list2.index(commonRestaurant)
		
		commonRestaurantsList =[]
		for restaurant in commonRestaurantsDict:
			if commonRestaurantsDict[restaurant] == min(commonRestaurantsDict.values()):
				commonRestaurantsList.append(restaurant)
		
		return commonRestaurantsList

if __name__ == '__main__':
	print(findRestaurant(["Shogun", "Tapioca Express", "Burger King", "KFC"],["Piatti", "The Grill at Torrey Pines", "Hungry Hunter Steakhouse", "Shogun"]))
	print(findRestaurant(["Shogun", "Tapioca Express", "Burger King", "KFC"],["KFC", "Shogun", "Burger King"]))
	