Collections:

TREEMAP

To assist Event organizers, you need to develop a console application that shows the number of tickets sold in a particular price category.

Sample Input and Output :
[All Texts in bold corresponds to the input and rest are output]

Enter the number of events:
3
Enter event details in CSV(Customer Name,Ticket Price,No of Seats Booked)
Emily,100,5
Natalie,200,10
Grace,100,3
Ticket Price    Tickets Booked
100                 8
200                 10

CODE:

//package com.mycom.collections.map;

import java.util.Scanner;

import java.util.Set;

import java.util.TreeMap;

public class Main {

    public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

System.out.println("Enter the number of events:");

int num = Integer.parseInt(sc.nextLine());

TreeMap<Integer,Integer> tm = new TreeMap<Integer,Integer>();

System.out.println("Enter event details in CSV(Customer Name,Ticket Price,No of Seats Booked)");

for(int i =0; i<num; i++) {

String user = sc.nextLine();

String arr[]=user.split(",");

            int price=Integer.parseInt(arr[1]);

            int seats=Integer.parseInt(arr[2]);

            if(tm.containsKey(price)){

                Integer s1 = tm.get(price);

                seats=seats+s1;   

                tm.replace(price,s1,seats);     //replace(key,old value,new value);

            }else{

                tm.put(Integer.parseInt(arr[1]),Integer.parseInt(arr[2]));

            }

}

System.out.println(String.format("%-15s %s","Ticket Price","Tickets Booked"));

Set<Integer> keys = tm.keySet();

for(Integer k:keys) {

System.out.println(String.format("%-15s %s",k,tm.get(k)));

}

}

}