UnsortedHashSet.java

import java.util.LinkedList;
import java.lang.reflect.Array;

public class UnsortedHashSet<E> {
   
    private static final double LOAD_FACTOR_LIMIT = 0.7;
    
    private int size;
    private LinkedList<E>[] con;
    
    public UnsortedHashSet() {
        con  = (LinkedList<E>[])(new LinkedList[10]);
    }
    
    public boolean add(E obj) {
        int oldSize = size;
        int index = Math.abs(obj.hashCode()) % con.length;
        if(con[index] == null)
            con[index] = new LinkedList<E>();
        if(!con[index].contains(obj)) {
            con[index].add(obj);
            size++;
            
        }
        if(1.0 * size / con.length > LOAD_FACTOR_LIMIT)
            resize();
        return oldSize != size;
    }

    private void resize() {
        UnsortedHashSet<E> temp = new UnsortedHashSet<E>();
        temp.con = (LinkedList<E>[])(new LinkedList[con.length * 2 + 1]);
        for(int i = 0; i < con.length; i++){
            if(con[i] != null)
                for(E e : con[i])
                    temp.add(e);
        }
        con = temp.con;
    }
    
    public int size() {
        return size;
    }
}