244.Shortest Word Distance II

    /*
     *244.Shortest Word Distance II 
     *2016-6-18 by Mingyang
     *就是利用一个Map来存所有的数据，直接取就好了
     */
    class WordDistance {
        private Map<String, List<Integer>> map = new HashMap<String, List<Integer>>();
        public WordDistance(String[] words) {
            for (int i = 0; i < words.length; i++) {
                String s = words[i];
                List<Integer> list;
                if (map.containsKey(s)) {
                    list = map.get(s);
                } else {
                    list = new ArrayList<Integer>();
                }
           //就算新加的数也不要忘了加到list里面
                list.add(i);
                map.put(s, list);
            }
        }
        public int shortest(String word1, String word2) {
            List<Integer> l1 = map.get(word1);
            List<Integer> l2 = map.get(word2);
            int min = Integer.MAX_VALUE;
         //Java 5以后才有的循环表达，可int也可Integer
            for (int a : l1) {
                for (int b : l2) {
                    min = Math.min(Math.abs(b - a), min);
                }
            }
            return min;
        }
    }