Leetcode 243: Shortest Word Distance

最短单词距离算法

最新推荐文章于 2021-02-22 15:58:50 发布

转载最新推荐文章于 2021-02-22 15:58:50 发布 · 53 阅读

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原文链接：http://www.cnblogs.com/liangmou/p/8056398.html

本文介绍了一种算法，用于计算给定列表中两个特定单词之间的最短距离。通过使用字典来存储每个单词出现的位置，该算法能有效地找到两个目标单词最近的相邻位置，并返回它们之间的距离。

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.

 1 public class Solution {
 2     public int ShortestDistance(string[] words, string word1, string word2) {
 3         var dict = new Dictionary<string, IList<int>>();
 4         
 5         int i = 0, j = 0;
 6         for (i = 0; i < words.Length; i++)
 7         {
 8             if (!dict.ContainsKey(words[i]))
 9             {
10                 dict[words[i]] = new List<int>();
11             }
12             
13             dict[words[i]].Add(i);
14         }
15         
16         IList<int> l1 = dict[word1], l2 = dict[word2];
17         int min = Int32.MaxValue;
18         i = 0;
19         
20         while (i < l1.Count && j < l2.Count)
21         {
22             min = Math.Min(min, Math.Abs(l1[i] - l2[j]));
23             
24             if (l1[i] >= l2[j])
25             {
26                 j++;
27             }
28             else
29             {
30                 i++;
31             }
32         }
33         
34         return min;
35     }
36 }