Shortest Word Distance 解答

Question

Given a list of words and two words word1 and word2, return the shortest distance between these two words in the list.

For example,
Assume that words = ["practice", "makes", "perfect", "coding", "makes"].

Given word1 = “coding”, word2 = “practice”, return 3.
Given word1 = "makes", word2 = "coding", return 1.

Note:
You may assume that word1 does not equal to word2, and word1 and word2 are both in the list.

Solution

双指针的方法。last_word1为word1最后一次出现的坐标。last_word2为word2最后一次出现的坐标。所以当last_word1变化时，我们计算last_word1 - last_word2 + 1，并且和当前最小值比较更新。Same to last_word2.

class Solution(object):
    def shortestDistance(self, words, word1, word2):
        """
        :type words: List[str]
        :type word1: str
        :type word2: str
        :rtype: int
        """
        last_word1 = -1
        last_word2 = -1
        length = len(words)
        result = length
        for i in range(length):
            if words[i] == word1:
                last_word1 = i
                if last_word2 != -1:
                    result = min(result, last_word1 - last_word2)
            elif words[i] == word2:
                last_word2 = i
                if last_word1 != -1:
                    result = min(result, last_word2 - last_word1)
        return result