package algorithm;

import java.util.PriorityQueue;

public class PriorityQueueDemo {

    public static void main(String[]args){
        PriorityQueue pq=new PriorityQueue();
        Student st1=new Student();
        st1.id=1;
        Student st2=new Student();
        st2.id=2;
        Student st3=new Student();
        st3.id=3;
        pq.add(st1);
        pq.add(st2);
        pq.add(st3);
        System.out.println(((Student)pq.peek()).id);
    }
}

class Student implements Comparable{
    int id;
    @Override
    public int compareTo(Object o) {
        Student st=(Student)o;
        if(this.id< st.id){
            return 1;
        }else if(this.id>st.id){
            return -1;
        }
        return 0;
    }
}