개발자 Lim

비추천 하는 방법

	TreeMap<Integer,Integer> tmap = new TreeMap<Integer,Integer>();
         for (int cookie:s) {
            if(tmap.containsKey(cookie))
                tmap.put(cookie,tmap.get(cookie)+1);
            else
                tmap.put(cookie,1);

https://stackoverflow.com/questions/8923251/what-is-the-time-complexity-of-hashmap-containskey-in-java

추천 하는 방법

TreeMap<Integer,Integer> tmap = new TreeMap<Integer,Integer>();
for (int cookie:s) {
            Integer n = tmap.get(cookie);
            n = n==null?0:n;
            tmap.put(cookie,n+1);
        }