Minimum Index Sum of Two Lists

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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:

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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:

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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.

Solution

Python

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class Solution(object):
    def findRestaurant(self, list1, list2):
        """
        :type list1: List[str]
        :type list2: List[str]
        :rtype: List[str]
        """
        dic_list1 = dict(zip(list1,[index for index in range(len(list1))]))
        res = []
        least_sum = None
        for index,value in enumerate(list2):
            if value in dic_list1.keys():
                dic_list1[value] += index
                if least_sum is None:
                    least_sum = dic_list1[value]
                    res.append(value)
                elif least_sum > dic_list1[value]:
                        least_sum = dic_list1[value]
                        res = []
                        res.append(value)
                elif least_sum == dic_list1[value]:
                    res.append(value)
        return res

如果不理解的话可以看讨论区一段代码 Minimum Index Sum of Two Lists

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def findRestaurant(self, A, B):
    Aindex = {u: i for i, u in enumerate(A)}
    best, ans = 1e9, []

    for j, v in enumerate(B):
        i = Aindex.get(v, 1e9)
        if i + j < best:
            best = i + j
            ans = [v]
        elif i + j == best:
            ans.append(v)
    return ans