Linkedin Interview - Shortest distance between two words

/* This class will be given a list of words (such as might be tokenized
 * from a paragraph of text), and will provide a method that takes two
 * words and returns the shortest distance (in words) between those two
 * words in the provided text. 
 * Example:
 *   WordDistanceFinder finder = new WordDistanceFinder(Arrays.asList("the", "quick", "brown", "fox", "quick"));
 *   assert(finder.distance("fox","the") == 3);
 *   assert(finder.distance("quick", "fox") == 1);
 * /

public int findShortestDist(String[] words, String wordA, String wordB) {
	int n = words.length;
	int dist = n;
	int posA = -1, posB = -1;
	for(int i=0; i<n; i++) {
		if(words[i].equals(wordA)) {
			posA = i;
			if(posB != -1) {
				dist = Math.min(dist, posA-posB);
			}
		} else if(words[i].equals(wordB)) {
			posB = i;
			if(posA != -1) {
				dist = Math.min(dist, posB-posA);
			}
		}
	}
	return (posA == -1 || posB == -1) ? -1 : dist;
}

另外一种简单的写法：

public int findShortestDist(String[] words, String wordA, String wordB) {
	int n = words.length;
	int dist = n+1;
	int posA = -1, posB = -1;
	for(int i=0; i<n; i++) {
		if(words[i].equals(wordA)) {
			posA = i;
		} else if(words[i].equals(wordB)) {
			posB = i;
		}
		if(posA != -1 && posB != -1) {
			dist = Math.min(dist, Math.abs(posA-posB));
		}
	}
	return dist > n ? -1 : dist;
}

Reference:

http://www.careercup.com/question?id=5725709041401856

http://www.geeksforgeeks.org/find-the-minimum-distance-between-two-numbers/