VIP | ! 别 Fork 了！超过一定数量就跑路！‍ Gone | Continuous Deployment library

/*********************************
* Class: MAGSHIMIM C2            *
* Week:                          *
* Name:                          *
* Credits:                       *
**********************************/

#include 
#include 
#include 

#define STR_LEN 20

//Structs
typedef struct personNode
{
    char name[STR_LEN];
    int age;
    struct personNode* next;
} personNode;

//Functions
void insertPersonQueue(personNode** first, personNode* newNode);
void insertAtEnd(personNode** first, personNode* newNode);
personNode* createPerson(char name[], int age);
int listLength(personNode* curr);
void myFgets(char str[], int n);
void printList();

//Global variables
char* friends[3];

int main(void)
{
    personNode* first = NULL;
    int userInput = 0;

    while (userInput != 7)
    {
        printf("\nWelcome to MagshiParty Line Management Software!\nPlease enter your choice from the following options :\n1 - Print line\n2 - Add person to line\n3 - Remove person from line\n4 - VIP guest\n5 - Search in line\n6 - Reverse line\n7 - Exit\n");
        scanf("%d", &userInput);
        getchar();

        if (userInput == 2)
        {
            printf("Welcome guest!\n");
            char name[STR_LEN];
            int age, listLenVar;

            printf("Enter name: ");
            myFgets(name, STR_LEN);
            printf("Enter age: ");
            scanf("%d", &age);
            getchar();

            personNode* newPerson = createPerson(name, age);
            insertAtEnd(&first, newPerson);

            printf("Enter names of 3 friends:\n");
            for (int i = 0; i < 3; i++)
            {
                printf("Friend %d: ", i + 1);
                myFgets(name, STR_LEN);
                friends[i] = (char*)malloc(STR_LEN);
                strcpy(friends[i], name);
            }
            insertPersonQueue(&first, newPerson);
            printList(first);
        }
        else if (userInput == 1)
        {
            int listLenVar = listLength(first);
            printf("%d people in line\n", listLenVar);
            printList(first);
        }
        else if (userInput == 3)
        {
            printf("NOT WRITTEN YET!\n");
        }
        else if (userInput == 4)
        {
            printf("NOT WRITTEN YET!\n");
        }
        else if (userInput == 5)
        {
            printf("NOT WRITTEN YET!\n");
        }
        else if (userInput == 6)
        {
            printf("NOT WRITTEN YET!\n");
        }
    }
    getchar();
    return 0;
}

/**
Function will add a person to the list
input:
newNode - the new person to add to the list
output:
none
*/
void insertAtEnd(personNode** first, personNode* newNode)
{
    if (!*first)
    {
        *first = newNode;
    }
    else
    {
        personNode* p = *first;
        while (p->next)
        {
            p = p->next;
        }
        p->next = newNode;
    }
}

/**
Function will print a list of persons
input: the list (the first person)
output:
none
*/
void printList(personNode* first)
{
    personNode* curr = first;
    while (curr) // when curr == NULL, that is the end of the list, and loop will end (NULL is false)
    {
        printf("Name: %s, Age: %d\n", curr->name, curr->age);
        curr = curr->next;
    }
}

/**
Function will count the length of the list using recursion
input:
head of the list
output:
none
*/
int listLength(personNode* curr)
{
    int ans = 0;
    if (curr)
    {
        ans = 1 + listLength(curr->next);
    }
    return ans;
}

/**
Function will create a person
input:
person name and his age
output:
the person updated with correct information
*/
personNode* createPerson(char name[], int age)
{
    personNode* newPerson = (personNode*)malloc(sizeof(personNode));

    strncpy(newPerson->name, name, STR_LEN);
    newPerson->age = age;
    newPerson->next = NULL;

    return newPerson;
}

/**
Function will insert a person to the linked lists
if their friend is in the list then it will add that person right before there friend
if he has more than 2 friends that are in the lists it will add him behind the one that is the nearest to the first
input:
double pointer to the first list in the linked lists (the head)
and a pointer to the new list that wanted to be inserted
output:
none
*/
void insertPersonQueue(personNode** first, personNode* newNode)
{
    int fOne = 0, fTwo = 0, fThree = 0, pos = 0;
    if (!*first)
    {
        *first = newNode;
    }
    else
    {
        personNode* p = *first;
        personNode* loopP = *first;
        while (p)
        {
            if (strcmp(p->name, friends[0]) == 0)
            {
                fOne = 1;
                fOne += pos;
            }
            else if (strcmp(p->name, friends[1]) == 0)
            {
                fTwo = 1;
                fTwo += pos;
            }
            else if (strcmp(p->name, friends[2]) == 0)
            {
                fThree = 1;
                fThree += pos;
            }
            p = p->next;
            pos++;
        }

        if (fOne >= fTwo && fOne >= fThree && fOne > 0)
        {
            for (int i = 0; i < fOne - 1; i++)
            {
                loopP = loopP->next;
            }

            printf("new next changed to - %s\nloopP next changed to %s\n", loopP->next->name, newNode->name);
            newNode->next = loopP->next;
            loopP->next = newNode;
            
        }
    }
}

/*
Function will perform the fgets command and also remove the newline
that might be at the end of the string - a known issue with fgets.
input: the buffer to read into, the number of chars to read
*/
void myFgets(char* str, int n)
{
    fgets(str, n, stdin);
    str[strcspn(str, "\n")] = 0;
}