import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;


public class Jaccard {

    public <T> double calculation(Set<T> setA, Set<T> setB){

        Set<T> intersection = new HashSet<>(setA);
        intersection.retainAll(setB);   //積集合

        Set<T> union = new HashSet<>(setA);
        union.addAll(setB); //和集合

        double similarity = (double) intersection.size() / union.size();

        return similarity;
    }

    private void debug(){
        Set<String> setA = new HashSet<>();
        Set<String> setB = new HashSet<>();

        setA.add("リンゴ");
        setA.add("ミカン");

        setB.add("リンゴ");
        setB.add("バナナ");

        double sim = jaccard.calculation(setA, setB);
        System.out.println(sim);
    }

    public static void main(String[] args) throws IOException{
        Jaccard jaccard = new Jaccard();
        jaccard.debug();
    }
}