این کد رو برام توضیح بده



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

#define MAX_DOCTORS 5
#define MAX_APPOINTMENTS 10

// Structure to store doctor information
struct Doctor {
    char name[50];
    char specialization[50];
    int available_slots;
    char appointment_slots[MAX_APPOINTMENTS][20]; // Time slots for appointments
};

// Structure to store appointment information
struct Appointment {
    char patient_name[50];
    char doctor_name[50];
    char date[20];
    char time[10]; // Appointment time
};

// Function declarations
void viewDoctors(struct Doctor doctors[], int count);
void bookAppointment(struct Doctor doctors[], int doctorCount, struct Appointment appointments[], int *appointmentCount);
void viewAppointments(struct Appointment appointments[], int appointmentCount);
void cancelAppointment(struct Doctor doctors[], int doctorCount, struct Appointment appointments[], int *appointmentCount);
void initializeDoctors(struct Doctor doctors[]);

int main() {
    struct Doctor doctors[MAX_DOCTORS];
    struct Appointment appointments[MAX_APPOINTMENTS];
    int appointmentCount = 0;
    int choice;

    // Initialize doctors with data and time slots
    initializeDoctors(doctors);

    while (1) {
        // Menu options
        printf("\n--- Online Doctor Appointment System ---\n");
        printf("1. View Available Doctors\n");
        printf("2. Book an Appointment\n");
        printf("3. View Your Appointments\n");
        printf("4. Cancel an Appointment\n");
        printf("5. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                viewDoctors(doctors, MAX_DOCTORS);
                break;
            case 2:
                bookAppointment(doctors, MAX_DOCTORS, appointments, &appointmentCount);
                break;
            case 3:
                viewAppointments(appointments, appointmentCount);
                break;
            case 4:
                cancelAppointment(doctors, MAX_DOCTORS, appointments, &appointmentCount);
                break;
            case 5:
                printf("Exiting the system...\n");
                return 0;
            default:
                printf("Invalid choice! Please enter a valid option.\n");
        }
    }

    return 0;
}

// Function to initialize doctors with available appointment slots
void initializeDoctors(struct Doctor doctors[]) {
    strcpy(doctors[0].name, "Dr. John Smith");
    strcpy(doctors[0].specialization, "Cardiologist");
    doctors[0].available_slots = 5;
    strcpy(doctors[0].appointment_slots[0], "10:00 AM");
    strcpy(doctors[0].appointment_slots[1], "11:00 AM");
    strcpy(doctors[0].appointment_slots[2], "12:00 PM");
    strcpy(doctors[0].appointment_slots[3], "02:00 PM");
    strcpy(doctors[0].appointment_slots[4], "03:00 PM");

    strcpy(doctors[1].name, "Dr. Emily Davis");
    strcpy(doctors[1].specialization, "Dermatologist");
    doctors[1].available_slots = 3;
    strcpy(doctors[1].appointment_slots[0], "09:00 AM");
    strcpy(doctors[1].appointment_slots[1], "10:00 AM");
    strcpy(doctors[1].appointment_slots[2], "11:00 AM");

    strcpy(doctors[2].name, "Dr. William Brown");
    strcpy(doctors[2].specialization, "Pediatrician");
    doctors[2].available_slots = 4;
    strcpy(doctors[2].appointment_slots[0], "08:00 AM");
    strcpy(doctors[2].appointment_slots[1], "09:30 AM");
    strcpy(doctors[2].appointment_slots[2], "11:00 AM");
    strcpy(doctors[2].appointment_slots[3], "01:00 PM");

    strcpy(doctors[3].name, "Dr. Olivia Green");
    strcpy(doctors[3].specialization, "Orthopedic");
    doctors[3].available_slots = 2;
    strcpy(doctors[3].appointment_slots[0], "10:30 AM");
    strcpy(doctors[3].appointment_slots[1], "12:30 PM");

    strcpy(doctors[4].name, "Dr. Michael White");
    strcpy(doctors[4].specialization, "General Practitioner");
    doctors[4].available_slots = 6;
    strcpy(doctors[4].appointment_slots[0], "09:00 AM");
    strcpy(doctors[4].appointment_slots[1], "10:00 AM");
    strcpy(doctors[4].appointment_slots[2], "11:00 AM");
strcpy(doctors[4].appointment_slots[3], "01:00 PM");
    strcpy(doctors[4].appointment_slots[4], "02:00 PM");
    strcpy(doctors[4].appointment_slots[5], "03:00 PM");
}

// Function to view available doctors and their appointment slots
void viewDoctors(struct Doctor doctors[], int count) {
    printf("\n--- Available Doctors ---\n");
    for (int i = 0; i < count; i++) {
        printf("\nDoctor %d: %s (%s)\n", i + 1, doctors[i].name, doctors[i].specialization);
        printf("Available Slots: %d\n", doctors[i].available_slots);
        printf("Time Slots: ");
        for (int j = 0; j < MAX_APPOINTMENTS && doctors[i].appointment_slots[j][0] != '\0'; j++) {
            printf("%s ", doctors[i].appointment_slots[j]);
        }
        printf("\n");
    }
}

// Function to book an appointment
void bookAppointment(struct Doctor doctors[], int doctorCount, struct Appointment appointments[], int *appointmentCount) {
    int doctorChoice, slotChoice;
    char patientName[50], date[20];

    printf("\nEnter your name: ");
    scanf("%s", patientName);

    printf("Select a doctor by number (1-%d): ", doctorCount);
    scanf("%d", &doctorChoice);

    if (doctorChoice < 1 || doctorChoice > doctorCount) {
        printf("Invalid doctor choice!\n");
        return;
    }

    struct Doctor *selectedDoctor = &doctors[doctorChoice - 1];

    if (selectedDoctor->available_slots == 0) {
        printf("No available slots for this doctor.\n");
        return;
    }

    printf("Available time slots for %s:\n", selectedDoctor->name);
    for (int i = 0; i < MAX_APPOINTMENTS && selectedDoctor->appointment_slots[i][0] != '\0'; i++) {
        printf("%d. %s\n", i + 1, selectedDoctor->appointment_slots[i]);
    }

    printf("Select a time slot: ");
    scanf("%d", &slotChoice);

    if (slotChoice < 1 || slotChoice > selectedDoctor->available_slots) {
        printf("Invalid slot choice!\n");
        return;
    }

    printf("Enter the appointment date (dd/mm/yyyy): ");
    scanf("%s", date);

    // Store appointment details
    strcpy(appointments[*appointmentCount].patient_name, patientName);
    strcpy(appointments[*appointmentCount].doctor_name, selectedDoctor->name);
    strcpy(appointments[*appointmentCount].date, date);
    strcpy(appointments[*appointmentCount].time, selectedDoctor->appointment_slots[slotChoice - 1]);
    (*appointmentCount)++;

    // Remove the booked slot
    for (int i = slotChoice - 1; i < MAX_APPOINTMENTS - 1; i++) {
        strcpy(selectedDoctor->appointment_slots[i], selectedDoctor->appointment_slots[i + 1]);
    }
    selectedDoctor->available_slots--;

    printf("Appointment booked successfully with %s on %s at %s.\n", selectedDoctor->name, date, selectedDoctor->appointment_slots[slotChoice - 1]);
}

// Function to view all booked appointments
void viewAppointments(struct Appointment appointments[], int appointmentCount) {
    if (appointmentCount == 0) {
        printf("No appointments found.\n");
        return;
    }
    printf("\n--- Booked Appointments ---\n");
    for (int i = 0; i < appointmentCount; i++) {
        printf("Appointment %d: %s with %s on %s at %s\n", i + 1, appointments[i].patient_name, appointments[i].doctor_name, appointments[i].date, appointments[i].time);
    }
}

// Function to cancel an appointment
void cancelAppointment(struct Doctor doctors[], int doctorCount, struct Appointment appointments[], int *appointmentCount) {
    int appointmentChoice;
    if (*appointmentCount == 0) {
        printf("No appointments to cancel.\n");
        return;
    }

    viewAppointments(appointments, *appointmentCount);
    printf("Enter the appointment number to cancel: ");
    scanf("%d", &appointmentChoice);

    if (appointmentChoice < 1 || appointmentChoice > *appointmentCount) {
        printf("Invalid appointment choice!\n");
        return;
    }

    // Retrieve the doctor related to the appointment and re-add the time slot
    struct Appointment *appointmentToCancel = &appointments[appointmentChoice - 1];
    for (int i = 0; i < doctorCount; i++) {
if (strcmp(doctors[i].name, appointmentToCancel->doctor_name) == 0) {
            strcpy(doctors[i].appointment_slots[doctors[i].available_slots], appointmentToCancel->time);
            doctors[i].available_slots++;
            break;
        }
    }

    // Remove the appointment
    for (int i = appointmentChoice - 1; i < *appointmentCount - 1; i++) {
        appointments[i] = appointments[i + 1];
    }
    (*appointmentCount)--;

    printf("Appointment cancelled successfully.\n");
}