import javax.swing.*;

class Person{
    private String name, lastName;
    private int age, id;

    public Person(){

    }
    public void setName(){
        name = JOptionPane.showInputDialog(null, "Enter your first and last name:");
    }
    public String getName(){
        return name;
    }
    public void setLastName(String lastName){
        this.lastName = lastName;
    }
    public String getLastName(){
        return lastName;
    }
    public void setAge(){
        age = Integer.parseInt(JOptionPane.showInputDialog(null, "Enter your age:"));
    }
    public int getAge(){
        return age;
    }
    public void setId(){
        id = Integer.parseInt(JOptionPane.showInputDialog(null, "Enter your Id number:"));
    }
    public int getId(){
        return id;
    }
    public String toString(){
        return "Id number: " + id + ", age: " + age + ", name: " + name;
    }
}
class SortAndSearch{
    Person[] person = new Person[6];

    public SortAndSearch(){

    }
    public void setArray(){
        String lastName;
        for(int i = 0; i < person.length; i++){
            person[i] = new Person();
            person[i].setName();
            person[i].setAge();
            person[i].setId();
        }
        for(int i = 0; i < person.length; i++){
            int characterCount = person[i].getName().length();
            for(int j =0; j < characterCount; j++){
                if(person[i].getName().charAt(j) == ' '){
                    lastName = person[i].getName().substring(j+1, characterCount);
                    person[i].setLastName(lastName);
                }
            }
        }
    }
    public void sortById(){
        Person temp;
        for(int i = 0; i < person.length-1; i++){
            for(int j = 0; j < person.length-i-1; j++){
                if(person[j].getId() > person[j+1].getId()){
                    temp = person[j];
                    person[j] = person[j+1];
                    person[j+1] = temp;
                }
            }
        }
    }
    public void sortByLastName(){
        Person temp;
        for(int i = 0; i < person.length-1; i++){
            for(int j =0; j < person.length-i-1; j++){
                if(exchange(person[j],person[j+1])){
                    temp = person[j];
                    person[j] = person[j+1];
                    person[j+1] = temp;
                }
            }
        }
    }
    private boolean exchange(Person a, Person b){
        int countA = a.getLastName().length();
        int countB = b.getLastName().length();
        for(int i = 0; i < Math.min(countA, countB); i++){
            if(a.getLastName().charAt(i) > b.getLastName().charAt(i))
                return true;
            if(a.getLastName().charAt(i) < b.getLastName().charAt(i))
                return false;
        }
        if(countA > countB)
            return true;
        else
            return false;
    }
    public void searchByLastName(char firstLetter){
        String result = "";
        for(int i = 0; i < person.length; i++){
            if(person[i].getLastName().charAt(0) == firstLetter)
                result += person[i] + "\n";
        }
        if(result.equals(""))
            System.out.println("No last names starting with letter " + firstLetter + ".\n");
        else
            System.out.println(result);
    }
    public void searchByAge(int age){
        String result = "";
        for(int i = 0; i < person.length; i++){
            if(person[i].getAge() > age)
                result += person[i] + "\n";
        }
        if(result.equals(""))
            System.out.println("No ages above " + age + ".\n");
        else
            System.out.println(result);
    }
}