Leetcode 0243: Shortest Word Distance

题目描述：

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.

Time complexity: O(nm)
用两个指针index1和index2分别记录word1和word2最近出现的位置，每次找到新的单词是二者中的一个，则计算差值并与之前的差值比较取最小值。

class Solution {
    
    
    public int shortestDistance(String[] words, String word1, String word2) {
    
    
        int index1 = -1;
        int index2 = -1;
        int minDistance = words.length;
        for(int i = 0; i < words.length; i++){
    
    
            if(words[i].equals(word1)){
    
    
                index1 = i;
            }else if(words[i].equals(word2)){
    
    
                index2 = i;
            }
            if(index1 != -1 && index2 != -1){
    
    
                minDistance = Math.min(minDistance, Math.abs(index1-index2));
            }
        }
        return minDistance;
    }
}