Project — Hotel Management System

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Project Overview

This project models a small hotel with a fixed number of rooms. Each room is a struct holding its number, type, price, booking status, and guest name. The whole hotel is just an array of these structs — everything else is functions that read or modify that array.

Display All Rooms — prints a formatted table of every room's status
Book a Room — assigns a guest and number of nights to a free room
Check-out — calculates the final bill (with GST) and frees the room
Search Room — looks up a single room by number
Save to File — writes all room records to a text file for persistence

Concept used	Where
struct	Room record: number, type, price, status, guest, nights
Arrays	`Room hotel[TOTAL_ROOMS]` holds every room
Functions	One function per menu operation — keeps main() clean
switch-case	Routes the user's menu choice to the right function
File I/O	`fopen`/`fprintf` to persist room data
do-while	Keeps showing the menu until the user chooses Exit

part 1

Room Struct & Hotel Initialization

Data model

Every room is described by one Room struct. The whole hotel is a fixed-size array — TOTAL_ROOMS makes it easy to resize later. initHotel() pre-loads 5 rooms with realistic types and prices so the program has data to work with immediately.

Part 1 · hotel.c — structs & setup

hotel.c

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define TOTAL_ROOMS 5
#define GST 0.12

typedef struct {
    int   roomNo;
    char  type[20];
    float pricePerNight;
    int   isBooked;
    char  guestName[50];
    int   nights;
} Room;

Room hotel[TOTAL_ROOMS];   // the entire hotel lives in this array

void initHotel() {
    char *types[]  = {"Single", "Double", "Deluxe", "Suite", "Deluxe"};
    float prices[] = {1200, 2000, 3500, 6000, 3500};

    for (int i = 0; i < TOTAL_ROOMS; i++) {
        hotel[i].roomNo = 101 + i;
        strcpy(hotel[i].type, types[i]);
        hotel[i].pricePerNight = prices[i];
        hotel[i].isBooked = 0;
        strcpy(hotel[i].guestName, "-");
        hotel[i].nights = 0;
    }
}

💡 typedef struct lets us write Room instead of struct Room everywhere else in the file — purely a readability convenience.

part 2

Display, Search & Booking

Core operations

findRoomIndex() is the one helper everything else depends on — it turns a room *number* the user types into an *array index* we can actually use. Both booking and searching call it first before touching any data.

Part 2 · hotel.c — display, search, booking

hotel.c

void displayRooms() {
    printf("\n%-8s %-10s %-12s %-10s %-15s\n",
           "Room", "Type", "Price/Night", "Status", "Guest");
    for (int i = 0; i < TOTAL_ROOMS; i++) {
        printf("%-8d %-10s %-12.2f %-10s %-15s\n",
               hotel[i].roomNo, hotel[i].type, hotel[i].pricePerNight,
               hotel[i].isBooked ? "Booked" : "Free", hotel[i].guestName);
    }
}

int findRoomIndex(int roomNo) {
    for (int i = 0; i < TOTAL_ROOMS; i++)
        if (hotel[i].roomNo == roomNo)
            return i;
    return -1;   // not found
}

void bookRoom() {
    int roomNo, nights;
    char name[50];

    printf("Enter room number to book: ");
    scanf("%d", &roomNo);

    int idx = findRoomIndex(roomNo);
    if (idx == -1) { printf("Room not found.\n"); return; }
    if (hotel[idx].isBooked) { printf("Room already booked.\n"); return; }

    printf("Enter guest name: ");
    scanf(" %[^\n]", name);   // reads a full name with spaces
    printf("Enter number of nights: ");
    scanf("%d", &nights);

    hotel[idx].isBooked = 1;
    strcpy(hotel[idx].guestName, name);
    hotel[idx].nights = nights;

    printf("Room %d booked for %s (%d nights).\n", roomNo, name, nights);
}

void searchRoom() {
    int roomNo;
    printf("Enter room number to search: ");
    scanf("%d", &roomNo);

    int idx = findRoomIndex(roomNo);
    if (idx == -1) { printf("Room not found.\n"); return; }

    printf("Room %d | %s | Rs %.2f/night | %s | Guest: %s\n",
           hotel[idx].roomNo, hotel[idx].type, hotel[idx].pricePerNight,
           hotel[idx].isBooked ? "Booked" : "Free", hotel[idx].guestName);
}

⚠️ %[^\n] reads until a newline — this lets the guest name contain spaces (e.g. "Ravi Kumar"), which plain %s would cut off at the first space.

part 3

Checkout Billing & File Saving

Calculations + persistence

Checkout is where the project earns its keep: it computes nights × price, adds GST, prints an itemized bill, then resets the room to free. saveToFile() writes every room as a comma-separated line — simple, human-readable, and easy to re-load later.

Part 3 · hotel.c — billing & file I/O

hotel.c

void checkoutRoom() {
    int roomNo;
    printf("Enter room number to checkout: ");
    scanf("%d", &roomNo);

    int idx = findRoomIndex(roomNo);
    if (idx == -1) { printf("Room not found.\n"); return; }
    if (!hotel[idx].isBooked) { printf("Room already free.\n"); return; }

    float subtotal = hotel[idx].pricePerNight * hotel[idx].nights;
    float tax      = subtotal * GST;
    float total    = subtotal + tax;

    printf("\n----- Final Bill -----\n");
    printf("Guest : %s\n", hotel[idx].guestName);
    printf("Room  : %d (%s)\n", hotel[idx].roomNo, hotel[idx].type);
    printf("Nights: %d x Rs %.2f = Rs %.2f\n",
           hotel[idx].nights, hotel[idx].pricePerNight, subtotal);
    printf("GST(12%%): Rs %.2f\n", tax);
    printf("Total : Rs %.2f\n", total);

    // free the room for the next guest
    hotel[idx].isBooked = 0;
    strcpy(hotel[idx].guestName, "-");
    hotel[idx].nights = 0;
}

void saveToFile() {
    FILE *fp = fopen("hotel_data.txt", "w");
    if (!fp) { printf("Error saving file.\n"); return; }

    for (int i = 0; i < TOTAL_ROOMS; i++) {
        fprintf(fp, "%d,%s,%.2f,%d,%s,%d\n",
                hotel[i].roomNo, hotel[i].type, hotel[i].pricePerNight,
                hotel[i].isBooked, hotel[i].guestName, hotel[i].nights);
    }
    fclose(fp);
    printf("Data saved to hotel_data.txt\n");
}

💡 Reset after checkout. Setting isBooked = 0 and clearing the guest name/nights means the same array slot can be reused for the next guest — no need to add or remove array elements.

part 4

The Main Menu

do-while + switch

The main() function stays tiny on purpose — it just loops, shows the menu, and routes the choice to the right function. A do-while loop guarantees the menu shows at least once, and repeats until the user picks Exit.

Part 4 · hotel.c — main()

hotel.c

int main() {
    initHotel();
    int choice;

    do {
        printf("\n===== HOTEL MANAGEMENT SYSTEM =====\n");
        printf("1. Display All Rooms\n");
        printf("2. Book a Room\n");
        printf("3. Check-out & Generate Bill\n");
        printf("4. Search Room\n");
        printf("5. Save Data to File\n");
        printf("6. Exit\n");
        printf("Enter choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1: displayRooms();  break;
            case 2: bookRoom();      break;
            case 3: checkoutRoom();  break;
            case 4: searchRoom();    break;
            case 5: saveToFile();    break;
            case 6: printf("Exiting... Thank you!\n"); break;
            default: printf("Invalid choice.\n");
        }
    } while (choice != 6);

    return 0;
}

terminal — sample session

output

===== HOTEL MANAGEMENT SYSTEM =====
1. Display All Rooms
2. Book a Room
3. Check-out & Generate Bill
4. Search Room
5. Save Data to File
6. Exit
Enter choice: 1

Room     Type       Price/Night  Status     Guest
101      Single     1200.00      Free       -
102      Double     2000.00      Free       -
103      Deluxe     3500.00      Free       -
104      Suite      6000.00      Free       -
105      Deluxe     3500.00      Free       -

Enter choice: 2
Enter room number to book: 103
Enter guest name: Ravi Kumar
Enter number of nights: 3
Room 103 booked for Ravi Kumar (3 nights).

Enter choice: 3
Enter room number to checkout: 103

----- Final Bill -----
Guest : Ravi Kumar
Room  : 103 (Deluxe)
Nights: 3 x Rs 3500.00 = Rs 10500.00
GST(12%): Rs 1260.00
Total : Rs 11760.00

Enter choice: 6
Exiting... Thank you!

extend it

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Ways to Extend This Project

This version keeps things simple to focus on the core logic. Once it's working, these are natural next steps — each one maps to a concept from earlier lessons:

Load from file on startup — read hotel_data.txt with fscanf so data survives between runs
Dynamic room count — replace the fixed array with malloc-allocated memory sized from user input
Linked list of bookings — track booking *history* per room, not just the current guest
Search by guest name — linear search through the array matching strcmp on guest name
Sort rooms by price — plug in any sorting algorithm from the Sorting lesson
Admin login — add a password check before allowing booking/checkout

Extension	Concept it reuses
Persistent load/save	File I/O lesson
Dynamic rooms	Dynamic memory (malloc/realloc) lesson
Booking history	Linked Lists lesson
Sort by price	Sorting Algorithms lesson

✓

Project Checklist

I understand the Room struct and what each field stores
I can explain how findRoomIndex() connects room number to array index
I can trace bookRoom() end to end
I understand the GST billing calculation in checkoutRoom()
I know why the room is reset after checkout
I understand how saveToFile() writes each room as a CSV line
I can trace the do-while + switch main menu loop
I compiled and ran the full program myself
I picked at least one extension to try next