1.2018 KAKAO BLIND RECRUITMENT [1차] 뉴스 클러스터링

import java.util.*;

class Solution {
    public int solution(String str1, String str2) {
		ArrayList<String> set1 = new ArrayList<>();
		ArrayList<String> set2 = new ArrayList<>();
        
        str1 = str1.toUpperCase();
        str2 = str2.toUpperCase();
        
        List<String> inter = new ArrayList<>();
        List<String> union = new ArrayList<>();
        
        // START 여기서 
        for(int i=0; i<str1.length()-1; i++){
            String cur = str1.substring(i,i+2);
            if(cur.matches("^[a-zA-Z]*$")){
                set1.add(cur);
            }
        }
        
        for(int i=0; i<str2.length()-1; i++){
            String cur = str2.substring(i,i+2);
            if(cur.matches("^[a-zA-Z]*$")){
                set2.add(cur);
            }
        }
        
        int interSize = 0;
        
        for(String subStr1:set1){
            if(set2.remove(subStr1)){
                inter.add(subStr1);
                interSize++;
            }
        }
        // END 여기까지 핵심로직
        int unionSize = set2.size()+set1.size();
        if(unionSize == 0 ) return 65536;
        
        double ratio = (double) interSize / (double) unionSize;
        System.out.println(ratio+" "+ interSize+" "+unionSize);
        System.out.println(set1+"\n"+set2);
        
        int answer = (int) (65536*ratio);
        return answer;
    }
}