linklist.h

#include<stdio.h>
#include<stdlib.h>
typedef struct Node
{
    int val;
    struct Node *next;
} Node;

// initialize the linked list
Node *initialize()
{
    return NULL;
}

// create a new node
Node *createNode(int x)
{
    Node *node = (Node *)malloc(sizeof(Node));
    node->val = x;
    node->next = NULL;
}

// insert node at begining
void insert_beg(Node **start, int x)
{
    Node *newNode = createNode(x);
    if (*start != NULL)
    {
        newNode->next = *start;
    }
    *start = newNode;
}

// insert node at last
void insert_last(Node **start, int x)
{
    Node *newNode = createNode(x);
    if (*start == NULL)
    {
        *start = newNode;
    }
    else
    {
        Node *temp = *start;
        while (temp->next != NULL)
        {
            temp = temp->next;
        }
        temp->next = newNode;
    }
}
int count(Node *start)
{
    int count = 0;
    if (start == NULL)
        return 0;
    while (start != NULL)
    {
        count++;
        start = start->next;
    }
    printf("\nTotal Nodes : %d",count);
    return count;
}
void insert_pos(Node **start, int pos, int x)
{
    int totalNodes = count(*start);
    if (totalNodes+1 < pos)
    {
        printf("\nInvalid position %d, Available Position %d-%d",pos,1,totalNodes+1);
        return;
    }

    Node *newNode = createNode(x);
    if (pos == 1)
    {
        newNode->next = *start;
        *start = newNode;
    }else if(totalNodes+1 == pos ){
        insert_last(start,x);
    }
    else
    {
        Node *prev = *start;
        Node *current = (*start)->next;
        int p = 2;
        while (p <= pos-1 )
        {
            current = current->next;
            prev = prev->next;
            p++;
        }
        newNode->next = prev->next;
        prev->next = newNode;
    }
    printf("\nNode inserted at %d", pos);
}

Node * search(Node *start, int sval){
    Node *current  = start;
    while(current !=NULL){
        if(current->val == sval)
            return current;
    }
    printf("\nNode with %d value not found",sval);
    return NULL;

}

void insert_after(Node **start, int val, int x)
{
    Node *current = search(*start, val);
    if(current != NULL){
        Node *newNode = createNode(x);
        newNode->next = current->next;
        current->next = newNode;
        printf("\nNode inserted after %d",val);
    }
}

// check for the empty of linked list
int isEmpty(Node *start)
{
    if (start == NULL)
    {
        printf("\nEmpty List");
        return 1;
    }
    return 0;
}

// deleting the node
void del_beg(Node **start)
{
    if (!isEmpty(*start))
    {
        Node *temp = *start;
        *start = (*start)->next;
        printf("\n%d node deleted", temp->val);
        free(temp);
    }
}

// delete a node from last
void del_last(Node **start)
{
    if (!isEmpty(*start))
    {
        Node *temp = *start;
        if (temp->next == NULL)
        {
            printf("\n%d deleted node", temp->val);
            *start = NULL;
        }
        else
        {
            while (temp->next->next != NULL)
            {
                temp = temp->next;
            }
            printf("\n%d deleted node", temp->val);
            free(temp->next);
            temp->next = NULL;
        }
    }
}

// show all the nodes
void show(Node *start)
{
    if (!isEmpty(start))
    {
        printf("\nLinked list is\n");
        while (start != NULL)
        {
            printf("%d | %p\t", start->val, start->next);
            start = start->next;
        }
    }
}