question3.c

#define _CRT_SECURE_NO_WARNINGS

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

#define STR_MAX_LEN 20
#define FRIENDS_NUMBER 3

typedef struct personNode {
    char name[STR_MAX_LEN];
    int age;
    bool vip;
    struct personNode* next;
} personNode;

void freeLine(personNode* head);
void search(personNode* head);
void printLine(personNode* head);
void reverse(personNode** head_ref);
void removeFromLine(personNode** head);
void insertAtBegin(personNode** head, personNode* newNode);
void israeliInsertToLine(personNode** head, char names[][STR_MAX_LEN], personNode* newNode);
int printSelectMenu();
int lineLength(personNode* head);
personNode* addToLine(personNode* head);
personNode* addVIPToLine(personNode* head);


int main()
{
    int choice = 0;
    personNode* head = NULL;

    while (1)
    {
        choice = printSelectMenu();

        switch (choice)
        {
            case 1:
                printLine(head);
                break;
            case 2:
                head = addToLine(head);
                break;
            case 3:
                removeFromLine(&head);
                break;
            case 4:
                head = addVIPToLine(head);
                break;
            case 5:
                search(head);
                break;
            case 6:
                reverse(&head);
                break;
            case 7:
                printf("Goodbye!");
                freeLine(head);
                getchar();
                return 0;
        }
    }

    freeLine(head);
    getchar();
    return 0;
}
/*
* Prints the menu and returns the user selection
* input: -
* output: user selection
*/
int printSelectMenu()
{
    int choice = 0;

    printf("Welcome to MagshiParty Line Management Software!\n"
           "Please enter your choice from the following options :\n"
           "1 - Print line\n"
           "2 - Add person to line\n"
           "3 - Remove person from line\n"
           "4 - VIP guest\n"
           "5 - Search in line\n"
           "6 - Reverse line\n"
           "7 - Exit\n");
    scanf("%d", &choice);
    getchar();

    return choice;
}
/* Prints the line
* input: head of the line
* output: -
*/
void printLine(personNode* head)
{
    personNode* current_node = head;

    printf("%d people in line:\n", lineLength(head));

    while (current_node != NULL)
    {
        printf("Name: %s, Age: %d\n", current_node->name, current_node->age);
        current_node = current_node->next;
    }
}
/* Counts the length of the line
* input: the head of the line
* output: the length of the line
*/
int lineLength(personNode* head)
{
    if (!head)  // if list empty
    {
        return 0;
    }
    else
    {
        return 1 + lineLength(head->next);
    }
}
/* Inserts new node into the end of the main node
* input: head of the main node, new node
* output: -
*/
void insertAtEnd(personNode** head, personNode* newNode)
{
    if (!*head)
    {
        *head = newNode;
    }
    else
    {
        personNode* p = *head;
        while (p->next)
        {
            p = p->next;
        }
        p->next = newNode;
    }
}
/* Creates new node (type of - person)
* input: -
* output: -
*/
personNode* createPersonNode()
{
    personNode* newPersonNode = (personNode*)malloc(sizeof(personNode));

    strcpy(newPersonNode->name, "No name");
    newPersonNode->age = 0;
    newPersonNode->vip = false;
    newPersonNode->next = NULL;

    return newPersonNode;
}
/* Custom fgets() with built-in '\n' remove
* input: string to input, string size
* output: -
*/
void myFgets(char str[], int n)
{
    fgets(str, n, stdin);
    str[strcspn(str, "\n")] = 0;
}
/* asks user to input guest to add him into the line
* input: head of the line
* output: new head of the line
*/
personNode* addToLine(personNode* head)
{
    int i = 0;
    personNode* newNode = NULL;
    char friends[FRIENDS_NUMBER][STR_MAX_LEN] = { 0 };

    printf("Welcome guest!\n");

    newNode = createPersonNode();

    printf("Enter name: ");
    myFgets(newNode->name, STR_MAX_LEN);

    printf("Enter age: ");
    scanf("%d", &(newNode->age));
    getchar();

    printf("Enter name of 3 friends:\n");

    for (i = 0; i < FRIENDS_NUMBER; i++)
    {
        myFgets(friends[i], STR_MAX_LEN);
    }

    israeliInsertToLine(&head, friends, newNode);

    return head;
}
/* Inserts new node into the main node "Israeli line type"
* input: head of the main node, names of the friends (2d-array), new node
* output: -
*/
void israeliInsertToLine(personNode** head, char names[][STR_MAX_LEN], personNode* newNode)
{
    if (*head)
    {
        personNode* p = *head;
        if (0 == strcmp((*head)->name, names[0]) || 0 == strcmp((*head)->name, names[1]) || 0 == strcmp((*head)->name, names[2]))
        {
            newNode->next = (*head)->next;
            (*head)->next = newNode;
            return;
        }
        else
        {
            while (p->next &&
                (0 != strcmp(p->next->name, names[0]) || 0 != strcmp(p->next->name, names[1]) || 0 != strcmp(p->next->name, names[2])))
            {
                p = p->next;
            }
            if (p->next)
            {
                newNode->next = p->next;
                p->next = newNode;
                return;
            }
        }
    }
    insertAtEnd(head, newNode);
}
/* asks user to input guest to remove him from the line
* input: head of the node
* output: -
*/
void removeFromLine(personNode** head)
{
    char name[STR_MAX_LEN] = { 0 };
    printf("Enter name to remove:\n");
    myFgets(name, STR_MAX_LEN);
    personNode* p = *head;
    personNode* dNode = NULL;
    if (*head)
    {
        if (0 == strcmp((*head)->name, name))
        {
            *head = (*head)->next;
            free(p);
            printf("%s removed from line\n", name);
            return;
        }
        else
        {
            while (p->next &&
                0 != strcmp(p->next->name, name))
            {
                p = p->next;
            }
            if (p->next)
            {
                dNode = p->next;
                p->next = dNode->next;
                free(dNode);
                printf("%s removed from line\n", name);
                return;
            }
        }
    }
    printf("%s not in line\n", name);
}
/* asks user to input guest to add him into the begin of the line (VIP client)
* input: head of the main node
* output: new head with the new client
*/
personNode* addVIPToLine(personNode* head)
{
    personNode* newNode = NULL;

    printf("VIP GUEST!\n");

    newNode = createPersonNode();

    printf("Enter name: ");
    myFgets(newNode->name, STR_MAX_LEN);

    printf("Enter age: ");
    scanf("%d", &(newNode->age));
    getchar();

    insertAtBegin(&head, newNode);

    return head;
}
/* Inserts the new node into the begin of the head node
* input: head of the main node, new node
* output: -
*/
void insertAtBegin(personNode** head, personNode* newNode)
{
    if (!*head)
    {
        *head = newNode;
    }
    else
    {
        newNode->next = *head;
        *head = newNode;
    }
}
/* Reverses the given node
* input: node to reverse
* output: -
*/
void reverse(personNode** head)
{
    personNode* prev = NULL;
    personNode* current = *head;
    personNode* next = NULL;

    while (current) {
        // Store next
        next = current->next;

        // Reverse current node's pointer
        current->next = prev;

        // Move pointers one position ahead.
        prev = current;
        current = next;
    }
    *head = prev;
    printf("Line reversed!\n");
}
/* asks user to input string to search in the given node (line)
* input: head of the main node (line)
* output: -
*/
void search(personNode* head)
{
    char searchFor[STR_MAX_LEN ] = { 0 };
    printf("Enter name to search:\n");
    myFgets(searchFor, STR_MAX_LEN);

    personNode* current = head;  // Initialize current
    while (current != NULL)
    {
        if (strcmp(current->name, searchFor) == 0)
        {
            printf("%s in line\n", searchFor);
        }
        current = current->next;
    }
    printf("%s not in line\n", searchFor);
}
/* Frees the memory of the given node (line)
* input: head of the main node to free his memory
* output: -
*/
void freeLine(personNode* head)
{
    personNode* tmp;

    while (head)
    {
        tmp = head;
        head = head->next;
        free(tmp);
    }
}