244. Shortest Word Distance II

这几题都挺没意思的，建一个hashMap，里面存放出现过的位置的list

short稍微有点讲究，就是不要两个都重头找一遍，每次只移动小的那个

 

public class WordDistance {
    Map<String, List<Integer>> map;

    public WordDistance(String[] words) {
        map = new HashMap<String, List<Integer>>();
        for(int i = 0; i < words.length; i++) {
            if(map.containsKey(words[i])) {
                List<Integer> cur = map.get(words[i]);
                cur.add(i);
                map.put(words[i], cur);
            } else {
                List<Integer> cur = new ArrayList<Integer>();
                cur.add(i);
                map.put(words[i], cur);
            }
        }
    }

    public int shortest(String word1, String word2) {
        List<Integer> list1 = map.get(word1);
        List<Integer> list2 = map.get(word2);
        int i = 0; 
        int j = 0;
        int min = Integer.MAX_VALUE;
        while(i < list1.size() && j < list2.size()) {
            min = Math.min(min, Math.abs(list1.get(i) - list2.get(j)));
            if(list1.get(i) < list2.get(j)) {
                i++;
            } else {
                j++;
            }
        } 
        return min;
    }
}

// Your WordDistance object will be instantiated and called as such:
// WordDistance wordDistance = new WordDistance(words);
// wordDistance.shortest("word1", "word2");
// wordDistance.shortest("anotherWord1", "anotherWord2");