Answer to Question #227006 in C for Neil

Question

Write a menu driven single program, using switch case to perform the following operations in a single linked list by using different suitable user defined functions for each case.

[Ask the user "Do you want to continue (Press 1 or 0)"]

•Traverse the list

•Check if the list is empty [Call this to check underflow condition during the delete operation]

•Insert a node after a given data item

•Insert a node before a given data item

•Delete a node after a given data item

•Delete a node before a given data item

•Insert a node at the certain position (at beginning/end/any position)

•Delete a node at the certain position (at beginning/end/any position)

•Delete a node for the given key

•Search for an element in the linked list

•Sort the elements of the linked list

•Print the elements of the linked list in the reverse order

•Reverse the nodes of the linked list

•Print nth node from the last of a linked list

•Delete the duplicate elements in a linked list

Answer 1

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


struct Node
{
  int data;
  struct Node *next;
};
void TraverseList(struct Node *head)
{
  while (head != NULL)
  {
     printf(" %d ", head->data);
     head = head ->next;
  }
}
//Checking if the list is empty
int CheckEmpty(struct Node * head){
 	if(head!=NULL){
 		return 1;
	 }
	 else{
	 	return 0;
	 }
 }
 Node* insertBefore(Node* beforeNode, int val)
{
 
    
   
 
    
  Node *p, *n = head;
 
        
        for (n, p; n != beforeNode;
             p = n, n = n->next)
            ;
 
        
        Node* m = new Node(val);
 
        
        m->next = p->next;
 
        
        p->next = m;
 
        return m;
    
}
 
void deleteNode(struct Node** headRef, struct Node* dele)
{
  
    if (*headRef == NULL || dele == NULL)
        return;
 
   
    if (*headRef == dele)
        *headRef = dele->nextNode;
 
    
    if (dele->nextNode != NULL)
        dele->nextNode->prevNode = dele->prevNode;
 
    
    if (dele->prevNode != NULL)
        dele->prevNode->nextNode = dele->nextNode;
 
    
    free(dele);
}
 




void deleteNodeAtGivenPos(struct Node** headRef, int data)
{
    
    if (*headRef == NULL || data <= 0)
        return;
 
    struct Node* currentNode = *headRef;
    int i;
 
    
    for ( i = 1; currentNode != NULL && i < data; i++)
        currentNode = currentNode->nextNode;
 
    
    if (currentNode == NULL)
        return;
 
    
    deleteNode(headRef, currentNode);
}
 


 


void insertAfter(struct Node* prevNode, int newData)
{
    
    if (prevNode == NULL)
    {
      printf("Previous node cannot be null");
      return;
    }
 


    struct Node* newNode =(struct Node*) malloc(sizeof(struct Node));
 
    
    newNode->data  = newData;
 
    
    newNode->next = prevNode->next;
 
    
    prevNode->next = newNode;
}
 


int main()
{
  struct Node* head1 = NULL;
  int userChoice;
	printf("Do you want to continue. Press 0 or 1");
	scanf("%d", userchoice);
  
 
  return 0;

}