In the Zoho Round 3 coding challenge, one of the intriguing problems was to create a Call Taxi Booking Application. Here’s the exact question provided:
Question:
Design a call taxi booking application with the following constraints:
- There are 6 points (A, B, C, D, E, F) arranged linearly, and the distance between consecutive points is 15 km.
- The travel time between two consecutive points is 1 hour.
- All taxis start from point A.
- Minimum fare: Rs. 100 for the first 5 km. For every additional kilometer, Rs. 10 is charged.
- Allocate a free taxi that is closest to the customer. If two taxis are at the same distance, the one with lower earnings should be allotted.
- If no taxis are available, reject the booking.
- Display the earnings and booking details of each taxi after every booking.
This problem was an exciting mix of object-oriented programming and logical problem-solving. Here, I’ll walk you through the approach and solution.
What Is Zoho Round 3?
Zoho Round 3 is the programming round of Zoho’s hiring process, where candidates build a small working application in a language of their choice, usually within two to three hours. Unlike the earlier aptitude and basic coding rounds, Round 3 tests whether you can model a real problem with classes, handle the stated constraints, and produce output that matches the specification exactly.
The call taxi booking problem below is one of the most frequently reported Round 3 questions. The full Java solution follows, broken into three classes.
Table of Contents
Solution Approach
The application was designed with three core components:
- Taxi Class: Represents the state and functionality of each taxi.
- Booking Class: Represents individual booking details.
- TaxiBookingSystem Class: Manages the taxis and processes bookings.
1. Taxi Class
The Taxi class encapsulates details about the current state of a taxi, including its location, total earnings, and booking history.
import java.util.*;
class Taxi {
int id;
char currentPoint = 'A';
int totalEarnings = 0;
List<Booking> bookings = new ArrayList<>();
public Taxi(int id) {
this.id = id;
}
public boolean isAvailable(int requestTime) {
if (bookings.isEmpty()) return true;
Booking lastBooking = bookings.get(bookings.size() - 1);
return lastBooking.dropTime <= requestTime;
}
public int calculateEarnings(char from, char to) {
int distance = Math.abs(to - from) * 15;
return 100 + Math.max(0, (distance - 5) * 10);
}
public void addBooking(Booking booking) {
bookings.add(booking);
totalEarnings += booking.amount;
currentPoint = booking.to;
}
}2. Booking Class
The Booking class stores the details of a single booking, including pickup and drop locations, fare, and timings.
class Booking {
int bookingId, customerId, pickupTime, dropTime, amount;
char from, to;
public Booking(int bookingId, int customerId, char from, char to, int pickupTime, int dropTime, int amount) {
this.bookingId = bookingId;
this.customerId = customerId;
this.from = from;
this.to = to;
this.pickupTime = pickupTime;
this.dropTime = dropTime;
this.amount = amount;
}
}3. TaxiBookingSystem Class
The TaxiBookingSystem class integrates everything, handling booking requests and displaying taxi details.
public class TaxiBookingSystem {
static List<Taxi> taxis = new ArrayList<>();
static Scanner sc = new Scanner(System.in);
static int customerCounter = 1;
public static void main(String[] args) {
System.out.print("Enter number of taxis: ");
int numTaxis = sc.nextInt();
initializeTaxis(numTaxis);
while (true) {
System.out.println("\n1. Book Taxi\n2. Display Taxi Details\n3. Exit");
System.out.print("Enter your choice: ");
int choice = sc.nextInt();
switch (choice) {
case 1:
bookTaxi();
break;
case 2:
displayTaxiDetails();
break;
case 3:
System.out.println("Exiting...");
return;
default:
System.out.println("Invalid choice. Try again.");
}
}
}
public static void initializeTaxis(int n) {
for (int i = 1; i <= n; i++) {
taxis.add(new Taxi(i));
}
}
public static void bookTaxi() {
int customerId = customerCounter++;
System.out.print("Enter Pickup Point (A-F): ");
char pickup = sc.next().toUpperCase().charAt(0);
System.out.print("Enter Drop Point (A-F): ");
char drop = sc.next().toUpperCase().charAt(0);
System.out.print("Enter Pickup Time (in hours): ");
int pickupTime = sc.nextInt();
Taxi selectedTaxi = null;
int minDistance = Integer.MAX_VALUE;
for (Taxi taxi : taxis) {
if (taxi.isAvailable(pickupTime)) {
int distance = Math.abs(taxi.currentPoint - pickup);
if (distance < minDistance ||
(distance == minDistance && taxi.totalEarnings < selectedTaxi.totalEarnings)) {
selectedTaxi = taxi;
minDistance = distance;
}
}
}
if (selectedTaxi == null) {
System.out.println("Booking rejected. No taxis available.");
return;
}
int dropTime = pickupTime + Math.abs(drop - pickup);
int amount = selectedTaxi.calculateEarnings(pickup, drop);
int bookingId = selectedTaxi.bookings.size() + 1;
Booking booking = new Booking(bookingId, customerId, pickup, drop, pickupTime, dropTime, amount);
selectedTaxi.addBooking(booking);
System.out.println("Taxi-" + selectedTaxi.id + " is allocated.");
}
public static void displayTaxiDetails() {
for (Taxi taxi : taxis) {
System.out.println("Taxi-" + taxi.id + " Total Earnings: Rs." + taxi.totalEarnings);
System.out.printf("%-10s %-10s %-5s %-5s %-12s %-9s %-6s%n",
"BookingID", "CustomerID", "From", "To", "PickupTime", "DropTime", "Amount");
for (Booking booking : taxi.bookings) {
System.out.printf("%-10d %-10d %-5c %-5c %-12d %-9d %-6d%n",
booking.bookingId, booking.customerId, booking.from, booking.to,
booking.pickupTime, booking.dropTime, booking.amount);
}
}
}
}Sample Input and Output
Input 1:
Customer ID: 1, Pickup: A, Drop: B, Pickup Time: 9
Output 1:
Taxi-1 is allocated.
Input 2:
Customer ID: 2, Pickup: B, Drop: D, Pickup Time: 9
Output 2:
Taxi-2 is allocated.
Details:
Taxi-1 Total Earnings: Rs.200
BookingID CustomerID From To PickupTime DropTime Amount
1 1 A B 9 10 200Conclusion
This implementation demonstrates effective use of object-oriented principles, logical reasoning, and resource allocation. By encapsulating details in separate classes, the solution remains modular and scalable, making it suitable for real-world applications.
Frequently Asked Questions
What is Zoho Round 3?
Zoho Round 3 is the programming round of Zoho’s interview process. Candidates are given a problem statement with fixed constraints and asked to build a small working application, typically in two to three hours, using any language they are comfortable with.
How long is Zoho Round 3?
Most candidates report two to three hours for the programming round. The time is generous relative to the problem size, because Zoho is assessing how cleanly you model the problem rather than how fast you type.
What do Zoho interviewers look for in Round 3?
Correct handling of every stated constraint, a sensible class structure rather than one long main method, readable naming, and output that matches the required format exactly. Partial solutions that are well structured often score better than complete solutions that are messy.
Can I use any programming language in Zoho Round 3?
Yes. Java, C, C++ and Python are all commonly used. The solutions on this site are written in Java because it maps cleanly onto the class-based design these problems reward.
What happens after Zoho Round 3?
Candidates who clear the programming round usually move on to a technical discussion of their code, followed by an HR round. Be ready to explain your design choices and how you would extend the program.
