Practical-8 | DS | Circular Linked List.c

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

//todo Strcuture Definition
struct node
{
    int data;
    struct node *next;
};
struct node *head, *newnode, *temp, *prev, *prev1, *temp2;
// todo function prototyping
void normalCreation();  //?---1
void insertBeginning(); //*---2
void insertEnd();       //?---3
void insertBefore();    //*---4
void insertAfter();     //?---5
void deleteStart();     //*---6
void deleteEnd();       //?---7
void deleteBefore();    //*---8
void deleteAfter();     //?---9
void deleteNode();      //*---10
void searchNode();      //?---11
void display();         //*---12
//todo Function--Normal Creation -1 (Done)--tested
void normalCreation()
{
    int noOfElements;
    printf("\nEnter the No of Elements you want to add in the Linked List : ");
    scanf("%d", &noOfElements);
    for (int i = 0; i < noOfElements; i++)
    {
        newnode = (struct node *)malloc(sizeof(struct node));
        printf("\nEnter The Value you want to Add : ");
        scanf("%d", &newnode->data);
        if (head == NULL)
        {
            head = newnode;
            newnode->next = newnode;
        }
        else
        {
            temp = head;
            while (temp->next != head)
            {
                temp = temp->next;
            }
            newnode->next = head;
            temp->next = newnode;
        }
    }
}
//todo Function--Insert Beginning -2 (Done)--tested
void insertBeginning()
{
    newnode = (struct node *)malloc(sizeof(struct node));
    printf("\nEnter The Value you want to Add : ");
    scanf("%d", &newnode->data);
    temp = head;
    if (head == NULL)
    {
        head = newnode;
        newnode->next = newnode;
    }
    else
    {
        temp = head;
        while (temp->next != head)
        {
            temp = temp->next;
        }
        newnode->next = head;
        temp->next = newnode;
        head = newnode;
    }
}
//todo Function--Insert End -3 (Done)--tested
void insertEnd()
{
    newnode = (struct node *)malloc(sizeof(struct node));
    printf("\nEnter The Value you want to Add : ");
    scanf("%d", &newnode->data);
    newnode->next = NULL;
    if (head == NULL)
    {
        head = newnode;
        newnode->next = newnode;
    }
    else
    {
        temp = head;
        while (temp->next != head)
        {
            temp = temp->next;
        }

        temp->next = newnode;
        newnode->next = head;
    }
}
//todo Function--Insert before -4 (Done)--tested 
void insertBefore()
{

    if (head == NULL)
    {
        printf("\nYou need Atleast one Element in Linked List to Use This Function\n");
    }
    else
    {
        int num;
        printf("\nEnter the Data Before which you want to Insert the node : ");
        scanf("%d", &num);
        printf("\nEnter the value you want to add : ");
        newnode = (struct node *)malloc(sizeof(struct node));
        scanf("%d", &newnode->data);
        if (head->data == num)
        {
            temp = head;
            while (temp->next != head)
            {
                temp = temp->next;
            }
            newnode->next = head;
            temp->next = newnode;
            head = newnode;
        }
        else
        {
            temp = head;
            while (temp->data != num)
            {
                prev = temp;
                temp = temp->next;
            }
            prev->next = newnode;
            newnode->next = temp;
        }
    }
}
//todo Function--Insert After -5 (Done)--insert at start me bas error is coming
void insertAfter()
{
    if (head == NULL)
    {
        printf("\nYou need Atleast one Element in Linked List to Use This Function\n");
    }
    else
    {
        int num;
        printf("\nEnter the Data After which you want to Insert the node : ");
        scanf("%d", &num);
        printf("\nEnter the value you want to add : ");
        newnode = (struct node *)malloc(sizeof(struct node));
        scanf("%d", &newnode->data);
        if (head->data == num)
        {
            temp = head;
            while (temp->next != head)
            {
                temp = temp->next;
            }
            temp->next = newnode;
            newnode->next = head;
        }
        else
        {
            temp = head;
            while (temp->data != num)
            {
                temp = temp->next;
            }
            newnode->next = temp->next;
            temp->next = newnode;
        }
    }
}
//todo Function--Delete Start -6 ( done)--tested (had a bug that it cant remove last element if follwed ma'am's'pdf )
//todo to remove that bug added an else if separrately for only single element
void deleteStart()
{
    if (head == NULL)
    {
        printf("\nYou need Atleast one Element in Linked List to Use This Function\n");
    }
    else if (head->next == head) //means only one element
    {
        temp = head;
        printf("\nThe Element removed is : %d\n", temp->data);
        free(temp);
        head = NULL;
    }
    else
    {
        temp = head;
        while (temp->next != head)
        {
            temp = temp->next;
        }
        temp->next = head->next;
        printf("\nThe Element removed is : %d\n", head->data);
        free(head);
        head = temp->next;
    }
}
//todo Function--Delete End -7 (Done)--tested
void deleteEnd()
{
    if (head == NULL)
    {
        printf("\nYou need Atleast one Element in Linked List to Use This Function\n");
    }
    else if (head->next == head) //means only one element
    {
        temp = head;
        printf("\nThe Element removed is : %d\n", temp->data);
        free(temp);
        head = NULL;
    }
    else
    {
        temp = head;
        while (temp->next != head)
        {
            prev = temp;
            temp = temp->next;
        }
        prev->next = temp->next;
        printf("\nThe Element removed is : %d\n", temp->data);
        free(temp);
    }
}
//todo Function--Delete Before-8 (Done)--Done perfectly--tested
void deleteBefore()
{
    if (head == NULL || head->next == NULL)
    {
        printf("\nYou need Atleast Two Elements in Linked List to Use This Function\n");
    }
    else
    {
        int num;
        printf("\nEnter the Data Whose Before node you want to Delete : ");
        scanf("%d", &num);
        temp = head;
        temp2 = temp->next;
        if (temp2->data == num)
        {
            deleteStart();
        }
        else
        {
            temp = head;
            prev = temp;
            while (temp->data != num)
            {
                prev1 = prev;
                prev = temp;
                temp = temp->next;
            }
            prev1->next = temp;
            printf("\nThe Element removed is : %d\n", prev->data);
            free(prev);
        }
    }
}
//todo Function--Delete After Node-9 ()--tested ---(just the last element will not remove first)--else sahi hai
void deleteAfter()
{
    if (head == NULL || head->next == NULL)
    {
        printf("\nYou need Atleast Two Elements in Linked List to Use This Function\n");
    }
    else
    {
        int num;
        printf("\nEnter the Data Whose next node you want to Delete : ");
        scanf("%d", &num);
        temp = head;
        while (temp->data != num)
        {
            temp = temp->next;
        }
        prev = temp;
        temp = temp->next;
        if (temp->next == NULL)
        {
            prev->next = NULL;
        }
        prev->next = temp->next;
        printf("\nThe Element removed is : %d\n", temp->data);
        free(temp);
    }
}
//todo Function--Delete Specified Node-10 (Done)  --Still doubt(pura galat)
void deleteNode()
{
    if (head == NULL)
    {
        printf("\nYou need Atleast one Element in Linked List to Use This Function\n");
    }
    else
    {
        int num;
        printf("\nEnter the Data which you want to Delete from the Node : ");
        scanf("%d", &num);
        temp = head;
        if (head->data == num && head->next == NULL)
        {
            head = NULL;
            printf("\nThe Element removed is : %d\n", temp->data);
            free(temp);
        }
        else if (head->data == num && head->next != NULL)
        {
            head = head->next;
            printf("\nThe Element removed is : %d\n", temp->data);
            free(temp);
        }
        else
        {

            while (temp->data != num)
            {
                prev = temp;
                temp = temp->next;
            }
            if (temp->next = head)
            {
                deleteEnd();
            }
            else
            {
                prev->next = temp->next;
                printf("\nThe Element removed is : %d\n", temp->data);
                free(temp);
            }
        }
    }
}
//todo Function--Search A Node Function -11 (done)--tested
void searchNode()
{
    if (head == NULL)
    {
        printf("\nThe Linked List is Empty\n");
    }
    else
    {
        int num, counter = 0;
        printf("\nEnter the Data you want to search : ");
        scanf("%d", &num);
        temp = head;
        while (temp->data != num)
        {
            counter++;
            temp = temp->next;
        }
        printf("\nThe position of the node is : %d\n", counter);
    }
}
//todo Function--Display Function -12 (Done)--tested
void display()
{
    temp = head;
    while (temp->next != head)
    {
        printf("%d -> ", temp->data);
        temp = temp->next;
    }
    printf("%d & repeat", temp->data);
}
//todo main function--working (Done)
int main()
{
    head = NULL; //!NULL given to head pointer
    int option = 0;
    printf("\nThe Circular Linked List\n");
    printf("\n***--------Main Menu--------***");
    printf("\nPress the following keys for following functions");
    printf("\n1)  Initial Creation\n2)  Insert Begining\n3)  Insert End\n4)  Insert Before\n5)  Insert After\n6)  Delete Start\n7)  Delete End\n8)  Delete Before\n9)  Delete After\n10) Delete Specified Node\n11) Search Node\n12) Display\n13) Exit\n");
    do
    {
        printf("\nYou want to Perform Function No : ");
        scanf("%d", &option);
        switch (option)
        {
        case 1:
            normalCreation();
            break;
        case 2:
            insertBeginning();
            break;
        case 3:
            insertEnd();
            break;
        case 4:
            insertBefore();
            break;
        case 5:
            insertAfter();
            break;
        case 6:
            deleteStart();
            break;
        case 7:
            deleteEnd();
            break;
        case 8:
            deleteBefore();
            break;
        case 9:
            deleteAfter();
            break;
        case 10:
            deleteNode();
            break;
        case 11:
            searchNode();
            break;
        case 12:
            display();
            break;
        case 13:
            //! writing so that it does not come in default when we select option 12
            break;
        default:
            printf("\nInvalid Option key is pressed\n");
            break;
        }
    } while (option != 13);
    return 0;
}