[Java] HashMap

HashMap Iterators 예제 

static int sockMerchant(int n, int[] ar) {
        int result = 0;
 
        HashMap<Integer, Integer> hm = new HashMap<Integer, Integer>();
 
        for(int i=0;i<ar.length;i++){
            if(hm.containsKey(ar[i])){//socks 색이 이미 있는거라면?
                //int num=hm.get(ar[i]);
                hm.replace(ar[i],hm.get(ar[i])+1); //1 추가
            }else{
                hm.put(ar[i],1);//새로 추가하기
            }
        }
 
        Iterator<Integer> keys = hm.keySet().iterator();
        while( keys.hasNext() ){
            int key = keys.next();
            result+=hm.get(key)/2;
 
        }
        return result;
 
    }