题目

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.

难度

Easy

方法

用minSum保存最小的索引和，用一个dict记录list1中每个单词对应的索引序号。遍历list2，将值存入word中，计算word在list1和list2中的索引和，如果小于minSum，则替换minSum，并清空结果list，加入该word，如果==minSum，则直接加入word

python代码

import sys

class Solution(object):
    def findRestaurant(self, list1, list2):
        """
        :type list1: List[str]
        :type list2: List[str]
        :rtype: List[str]
        """
        list1Map = {}
        i = 0
        for word in list1:
            list1Map[word] = i
            i += 1

        minSum = sys.maxint
        i = 0
        restaurants = [] 
        for word in list2:
            if word in list1Map:
                if minSum > list1Map[word]+i:
                    print minSum
                    minSum = list1Map[word]+i
                    restaurants = []
                    restaurants.append(word)
                elif minSum == list1Map[word]+i:
                    restaurants.append(word)
            i += 1

        return restaurants

assert Solution().findRestaurant(["Shogun", "Tapioca Express", "Burger King", "KFC"], 
    ["Piatti", "The Grill at Torrey Pines", "Hungry Hunter Steakhouse", "Shogun"]) == ["Shogun"]
assert Solution().findRestaurant(["Shogun", "Tapioca Express", "Burger King", "KFC"], 
    ["KFC", "Shogun", "Burger King"]) == ["Shogun"]
assert Solution().findRestaurant(["Shogun","Tapioca Express","Burger King","KFC"], 
    ["KFC","Burger King","Tapioca Express","Shogun"]) == ["KFC","Burger King","Tapioca Express","Shogun"]