# 问题 原题链接：[https://leetcode.com/problems/shortest-word-distance/](https://leetcode.com/problems/shortest-word-distance/) Given a list of words and two words word1 and word2, return the shortest distance between these two words in the list. Example: Assume that words = ["practice", "makes", "perfect", "coding", "makes"]. ``` Input: word1 = “coding”, word2 = “practice” Output: 3 ``` ``` Input: word1 = "makes", word2 = "coding" Output: 1 ``` Note: - You may assume that word1 does not equal to word2, and word1 and word2 are both in the list. # 分析过程 - 输入：一个单词数组以及两个单词，这两个单词假定一定包含在数组内。 - 输出：这两个单词的最短距离。 - 思路：遍历数组，记录上次找到单词的索引，下次再找到时候做减法，见注释。 # 解决方法 ```swift class Solution { func shortestDistance(_ words: [String], _ word1: String, _ word2: String) -> Int { // 记录上次找到word1或者word2的索引 var lastIndex = -1 var result = Int.max for (i, word) in words.enumerated() { if word == word1 || word == word2 { // 首次进入先赋值 guard lastIndex > -1 else { lastIndex = i continue } // 上次找到的是word1或word2 // 如果上次找了word1，这次找到的还是word1，不更新 if words[lastIndex] != word { // 和上次找到的值做减法即可 result = min(result, i - lastIndex) } lastIndex = i } } return result } } ```