Shortest Word Distance

Source

1. leetcode

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.

Analysis

Record the index when word1 or word2 last appeared and update the min distance.

Complexity

Time: O(n)

Space: O(1)

Code

Java

public class Solution {
  public int shortestDistance(String[] words, String word1, String word2) {
    if (word1.equals(word2)) {
      return 0;
    }
    int index1 = -1;
    int index2 = -1;
    int minDistance = Integer.MAX_VALUE;
    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;
  }
}