Formatted question description: https://leetcode.ca/all/244.html
244 Shortest Word Distance II This is a follow up of Shortest Word Distance. The only difference is now you are given the list of words and your method will be called repeatedly many times with different parameters. How would you optimize it? Design a class which receives a list of words in the constructor, and implements a method that takes two words word1 and word2 and 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. @tag-array
Need to call the function to find the shortest word distance multiple times, then the solution to the previous problem is very inefficient.
Use HashMap to create a mapping between each word and all its appearing positions, and then when looking for the shortest word distance, you only need to take out the word’s mapped position array in HashMap for pairwise comparison.