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

struct node {
    int rollno;
    char name[50];
    struct node *next;
};

struct node *createNode(int rollno, char name[]) {
    struct node *newNode = (struct node *)malloc(sizeof(struct node));
    newNode->rollno = rollno;
    strcpy(newNode->name, name);
    newNode->next = NULL;
    return newNode;
}

struct node *insertPresident() {
    int roll;
    char name[50];
    printf("Enter President Roll No and Name:\n");
    scanf("%d", &roll);
    scanf("%s", name);
    struct node *president = createNode(roll, name);
    return president;
}

struct node *insertSecretary() {
    int roll;
    char name[50];
    printf("Enter Secretary Roll No and Name:\n");
    scanf("%d", &roll);
    scanf("%s", name);
    struct node *secretary = createNode(roll, name);
    return secretary;
}

void insertMember(struct node *head) {
    if (head == NULL) {
        printf("Club not created yet!\n");
        return;
    }
    int roll;
    char name[50];
    printf("Enter Member Roll No and Name:\n");
    scanf("%d", &roll);
    scanf("%s", name);
    struct node *member = createNode(roll, name);
    struct node *temp = head;
    while (temp->next->next != NULL) {  // stop before secretary
        temp = temp->next;
    }
    member->next = temp->next;
    temp->next = member;
    printf("Member added successfully!\n");
}

void display(struct node *head) {
    if (head == NULL) {
        printf("Club not created yet!\n");
        return;
    }
    struct node *temp = head;
    printf("\nClub Members:\n");
    while (temp != NULL) {
        printf("%d\t%s\n", temp->rollno, temp->name);
        temp = temp->next;
    }
}

int countMembers(struct node *head) {
    int count = 0;
    struct node *temp = head;
    while (temp != NULL) {
        count++;
        temp = temp->next;
    }
    return count;
}

struct node *deletePresident(struct node *head) {
    if (head == NULL) {
        printf("No President to delete!\n");
        return NULL;
    }
    struct node *temp = head;
    head = head->next;
    free(temp);
    printf("President deleted successfully!\n");
    return head;
}

struct node *deleteSecretary(struct node *head) {
    if (head == NULL || head->next == NULL) {
        printf("No Secretary to delete!\n");
        return head;
    }
    struct node *temp = head;
    while (temp->next->next != NULL) {
        temp = temp->next;
    }
    free(temp->next);
    temp->next = NULL;
    printf("Secretary deleted successfully!\n");
    return head;
}

// ✅ Delete specific member (by PRN)
struct node *deleteMember(struct node *head, int roll) {
    if (head == NULL) {
        printf("Club not created yet!\n");
        return NULL;
    }

    struct node *temp = head;
    struct node *prev = NULL;

    // Cannot delete president or secretary using this function
    if (head->rollno == roll) {
        printf("Cannot delete the President using this option!\n");
        return head;
    }

    // Traverse until second last (avoid deleting secretary)
    while (temp->next != NULL && temp->next->next != NULL) {
        if (temp->next->rollno == roll) {
            struct node *del = temp->next;
            temp->next = del->next;
            free(del);
            printf("Member deleted successfully!\n");
            return head;
        }
        temp = temp->next;
    }

    printf("Member not found or is Secretary!\n");
    return head;
}

struct node *mergeClubs(struct node *head1, struct node *head2) {
    if (head1 == NULL) {
        printf("Club 1 not created!\n");
        return NULL;
    }
    if (head2 == NULL) {
        printf("Club 2 not created!\n");
        return head1;
    }

    struct node *temp = head1;
    while (temp->next != NULL) {
        temp = temp->next;
    }
    temp->next = head2;
    printf("\nClubs merged successfully!\n");
    return head1;
}

int main() {
    struct node *head1 = NULL, *head2 = NULL;
    struct node *president, *secretary;
    int choice, c, roll;

    printf("\n=== CLUB MANAGEMENT SYSTEM ===\n");

    while (1) {
        printf("\nMenu:\n");
        printf("1. Create Club 1\n");
        printf("2. Create Club 2\n");
        printf("3. Insert Member\n");
        printf("4. Display Club\n");
        printf("5. Count Members\n");
        printf("6. Delete President\n");
        printf("7. Delete Secretary\n");
        printf("8. Delete Member\n");
        printf("9. Merge Clubs\n");
        printf("10. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                president = insertPresident();
                secretary = insertSecretary();
                president->next = secretary;
                head1 = president;
                printf("Club 1 created successfully!\n");
                break;

            case 2:
                president = insertPresident();
                secretary = insertSecretary();
                president->next = secretary;
                head2 = president;
                printf("Club 2 created successfully!\n");
                break;

            case 3:
                printf("Enter which club (1 or 2): ");
                scanf("%d", &c);
                if (c == 1)
                    insertMember(head1);
                else if (c == 2)
                    insertMember(head2);
                else
                    printf("Invalid club choice!\n");
                break;

            case 4:
                printf("Enter which club (1 or 2): ");
                scanf("%d", &c);
                if (c == 1)
                    display(head1);
                else if (c == 2)
                    display(head2);
                else
                    printf("Invalid club choice!\n");
                break;

            case 5:
                printf("Enter which club (1 or 2): ");
                scanf("%d", &c);
                if (c == 1)
                    printf("Total Members in Club 1: %d\n", countMembers(head1));
                else if (c == 2)
                    printf("Total Members in Club 2: %d\n", countMembers(head2));
                else
                    printf("Invalid club choice!\n");
                break;

            case 6:
                printf("Enter which club (1 or 2): ");
                scanf("%d", &c);
                if (c == 1)
                    head1 = deletePresident(head1);
                else if (c == 2)
                    head2 = deletePresident(head2);
                else
                    printf("Invalid club choice!\n");
                break;

            case 7:
                printf("Enter which club (1 or 2): ");
                scanf("%d", &c);
                if (c == 1)
                    head1 = deleteSecretary(head1);
                else if (c == 2)
                    head2 = deleteSecretary(head2);
                else
                    printf("Invalid club choice!\n");
                break;

            case 8:
                printf("Enter which club (1 or 2): ");
                scanf("%d", &c);
                printf("Enter Member Roll No to delete: ");
                scanf("%d", &roll);
                if (c == 1)
                    head1 = deleteMember(head1, roll);
                else if (c == 2)
                    head2 = deleteMember(head2, roll);
                else
                    printf("Invalid club choice!\n");
                break;

            case 9:
                if (head1 == NULL || head2 == NULL) {
                    printf("Both clubs must be created before merging!\n");
                } else {
                    head1 = mergeClubs(head1, head2);
                    printf("Merged Club:\n");
                    display(head1);
                }
                break;

            case 10:
                exit(0);

            default:
                printf("Invalid choice!\n");
        }
    }
    return 0;
}