leetcode 599. Minimum Index Sum of Two Lists

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:

1. The length of both lists will be in the range of [1, 1000].
2. The length of strings in both lists will be in the range of [1, 30].
3. The index is starting from 0 to the list length minus 1.
4. No duplicates in both lists.

没有看懂其意思，但是通过测试用例大概明白了它想干嘛！

class Solution(object):
    def findRestaurant(self, list1, list2):
        """
        :type list1: List[str]
        :type list2: List[str]
        :rtype: List[str]
        """        
        d1 = {s:i for i,s in enumerate(list1)} 
        d2 = {s:i for i,s in enumerate(list2)}
        
        ans = []
        min_sum = float('inf')
        for s in d1:
            if s in d2:
                sum2 = d1[s]+d2[s]
                if sum2 < min_sum:
                    min_sum = sum2
                    ans = [s]
                elif sum2 == min_sum:
                    ans.append(s)
        return ans        

还可以节省一个dict。

class Solution(object):
    def findRestaurant(self, list1, list2):
        """
        :type list1: List[str]
        :type list2: List[str]
        :rtype: List[str]
        """        
        d1 = {s:i for i,s in enumerate(list1)}         
        ans = []
        min_sum = float('inf')
        for i,s in enumerate(list2):
            if s in d1:
                sum2 = d1[s]+i
                if sum2 < min_sum:
                    min_sum = sum2
                    ans = [s]
                elif sum2 == min_sum:
                    ans.append(s)
        return ans