69_LinkedList_CodeChallenge-WriteAProgramThatDeleteTheNodeOfLinearLinkedListWithANegativeValue.c

-------> This program is incomplete
#include<stdio.h> 
#include <stdlib.h>
#include <conio.h>
// following is the specification of the structure 
typedef struct linklist
	 {
	  int no;
	  struct linklist *link;
	 } node;
char ch;
/* following is the definition of the create() function  that creates nodes for linked list
node *create(node *start)
	{
		node *temp,*p ;
		ch='y';
	//	clrscr();
		printf("\n\t\t **** INPUT BLOCK ****\n");
		if(start != NULL)
		  {
			printf("\n\n\t **** LIST ALREADY EXIST *****");
			getch();
			return(start);
		   }
		fflush(stdin);
		while(ch=='y')
		  {
		   temp=(node *)malloc(sizeof(node));
		   printf("\n\t Enter the no :==> " );
		   scanf("%d",&temp->no);
		   temp->link = NULL;
		   if(start == NULL)
			 p=start=temp ;
		   else
			{
			p->link=temp;
			p=temp;
			}
		   fflush(stdin);
		   printf("\t Do you want to continue (y/n) ? : ");
	 	   ch=getchar();
		  } // end of loop
		  return(start);
	 }
/* following is the definition of the function that displays all the nodes of the linked list */
void print(node *start)
	{
	 node *temp;
	// clrscr(); system("cls") ;
	 printf("\n\nBase address    Number     Link");
	 printf("\n===============================");
for(temp=start;temp != NULL;temp=temp->link)
printf("\n%10u  %10d  %10u",temp,temp->no,temp->link);
printf("\n\n\t Press any key to goto MAIN BLOCK.....");
	 getch();
	 return;
	}

/* definition of the function delf() that will be invoked to delete the first node */
node *delf(node *start)
   {
	node *tmp=start ;
	start=start->link;
	printf("\n\n\t Element is successfully deleted ");
	getch();
	free(tmp) ;  // garbage collection - deallocation of memory - reclaiming space
	return(start);
    }
 /* following is the definition of the function del_negative_node()
that finds a node with negative value and deletes it */
  
node *del_negative_node(node *start)
    {
	node *temp,*temp1;

	for(temp=start;(!(temp->no < 0))&& (temp != NULL);temp=temp->link)
	    temp1=temp;

	if(temp==NULL)  // no node with -ve value found in the linked list
	   {
		 printf("\n\n\t No node with negative value found in the Linklist");
		 getch();
		 return(start);
	   }

	if(temp==start)  // first node is -ve
	   start=delf(start);

	else       
	  {
		temp1->link=temp1->link->link;   /* temp1->link=temp->link */
		printf("\n\n\t Element with negative value is successfully deleted ");
		getch();
		free(temp) ; // garbage collection - deallocation of memory - reclaiming space
		return(start);
		   }
	 return(start);
	}

 				
 /* following is the definition of the function main() */ 	
 int main()
  {
node *start,*temp;  // declaration of pointer variables  
int op;
start=NULL;    // assigning NULL to start indicating linked list is empty
while(1)     // infinite loop
{
system("cls") ;    // clears the screen
printf("\n**************** Menu ***************");
printf("\n1) Create the linked list");
 printf("\n2) Delete a node with negative value") ;
 printf("\n3) Display the linked list");
printf("\n4) Exit");
printf("\nEnter your option please ");
scanf("%d",&op);   // reading choice from user
switch(op)
{
case 1:
 			start=create(start) ;   // calling the create() function
 	        break ;
 case 2:
            	start=del_negative_node(start); // calling the function to delete a node with negative value
				break;      		 

 case 3:			  
 	        print(start) ;  // calling the print() function()
			break ;
case  4: 
            exit(0) ;    // terminates the program			  
 	        
	 }    // end of switch case
}  // end of loop
}  // end of main()