Given a list of words and two wordsword1_and_word2, return the shortest distance between these two words in the list.

For example,
Assume that words =["practice", "makes", "perfect", "coding", "makes"].

Givenword1=“coding”,word2=“practice”, return 3.
Givenword1="makes",word2="coding", return 1.

Note:
You may assume thatword1does not equal toword2, and_word1_and_word2_are both in the list.

class Solution {
    public int shortestDistance(String[] words, String word1, String word2) {
        if (words == null || words.length == 0) return 0;

        int index1 = Integer.MIN_VALUE, index2 = Integer.MIN_VALUE;

        int ans = Integer.MAX_VALUE;
        for (int i = 0; i < words.length; i++){
            if (words[i].equals(word1)){
                if (index2 != Integer.MIN_VALUE){
                    ans = Math.min(ans, i - index2);    
                }
                index1 = i;
            }
            else if (words[i].equals(word2)){
                if (index1 != Integer.MIN_VALUE){
                    ans = Math.min(ans, i - index1);    
                }
                index2 = i;
            }
        }

        return ans;
    }
}