Coding-Problems/doubly linked list.c.txt at master · codesocbitd/Coding-Problems · GitHub

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#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
#include<malloc.h>
struct node
{
struct node*next;
int data;
struct node*prev;
};
struct node*start=NULL;
void createll();
void disp();
void insertbeg();
void insertend();
void deletebeg();
void deleteend();
void deletelist();
void main()
{
int ch;
do
{
printf("\n 1.create \n 2.display \n 3.insert in beginning \n 4. insert at end \n 5.delete beginning \n 6.delete at end \n 7.delete list");
printf("\n enter your choice");
scanf("%d", &ch);
switch(ch)
{
case 1: createll();
break;
case 2: disp();
break;
case 3: insertbeg();
break;
case 4: insertend();
break;
case 5: deletebeg();
break;
case 6: deleteend();
break;
case 7: deletelist();
break;
case 8: printf("\n exit");
break;
default: printf("\n invalid choice");
}
}
while(ch!=8);
getch();
}
void createll()
{ struct node*newnode,*ptr;
int num;
printf("\n enter -1 to end");
printf("\n enter the data");
scanf("%d",&num);
while(num!=-1)
{
if(start==NULL)
{
newnode=(struct node*)malloc(sizeof (struct node));
newnode->prev=NULL;
newnode->data=num;
newnode->next=NULL;
start=newnode;}
else
{
ptr=start;
newnode=(struct node*)malloc(sizeof (struct node));
newnode->data=num;
while(ptr->next!=NULL)
ptr=ptr->next;
ptr->next=newnode;
newnode->prev=ptr;
newnode->next=NULL;
}
printf("\n enter the data");
scanf("%d", & num);
}
getch();
}
void disp()
{
struct node*ptr;
ptr=start;
while(ptr!=NULL)
{
printf("\t %d", ptr->data);
ptr=ptr->next;
}
getch();
}
void insertbeg()
{
struct node*newnode;
int num;
printf("\n enter the data");
scanf("%d", &num);
newnode = (struct node*)malloc(sizeof (struct node));
newnode->data=num;
start->prev=newnode;
newnode->next=start;
newnode->prev=NULL;
start=newnode;
getch();
}
void insertend()
{
struct node*ptr,*newnode;
int num;
printf("\n enter the data");
scanf("%d", &num);
newnode = (struct node*) malloc (sizeof (struct node));
newnode->data=num;
ptr=start;
while(ptr->next!=NULL)
ptr=ptr->next;
ptr->next=newnode;
newnode->prev=ptr;
newnode->next=NULL;
getch();
}
void deletebeg()
{
struct node*ptr;
ptr=start;
start=start->next;
start->prev=NULL;
free(ptr);
getch();
}
void deletebeg()
{
struct node*ptr;
ptr=start;
while(ptr->next!=NULL)
ptr=ptr->next;
ptr->prev->next=NULL;
free(ptr);
getch();
}
void deletelist()
{
while(start!=NULL)
start=deletebeg(start);
getch();
}