#include<stdio.h>
#include<conio.h>
struct link
{
int data;
struct link*ptr;
};
typedef struct link node;
void main()
{
int size,i,choice;
char ch;
node*start,*temp,*p;
clrscr();
do
{
printf("enter the size of list:");
scanf("%d",&size);
printf("enter list\n");
start=NULL;
for(i=0;i<size;i++)
{
if(start==NULL)
{
start=(node*)malloc(sizeof(node));
scanf("%d",&start->data);
start->ptr=NULL;
}
else
{
for(p=start;p->ptr!=NULL;p=p->ptr);
temp=(node*)malloc(sizeof(node));
scanf("%d",&temp->data);
temp->ptr=NULL;
p->ptr=temp;
}
}
printf("Enter 1.To insert at the end\n");
printf("Enter 2.To insert at the beginning\n");
printf("Enter 3.To insert in between\n");
scanf("%d",&choice);
switch(choice)
{
case 1:
end(start,p);
break;
case 2:
beg(start,p);
break;
case 3:
between(start,p,size);
break;
default:
printf("wrong number entered\n");
}
printf("Enter y to continue\n");
scanf("%c",&ch);
}
while(ch=='Y'||ch=='y');
getch();
}
end(node*start,node*p)
{
node*temp;
for(p=start;p->ptr!=NULL;p=p->ptr)
temp=(node*)malloc(sizeof(node));
printf("enter the number to be inserted\n");
scanf("%d",&temp->data);
temp->ptr=NULL;
p->ptr=temp;
for(p=start;p!=NULL;p=p->ptr)
printf("%d",p->data);
return(0);
}
beg(node*start,node*p)
{
node*temp;
temp=(node*)malloc(sizeof(node));
printf("enter the number to be inserted\n");
scanf("%d",&temp->data);
temp->ptr=start;
start=temp;
printf("new linked list is:\n");
for(p=start;p!=NULL;p=p->ptr)
printf("%d",p->data);
return(0);
}
between(node*start,node*p,int size)
{
node*temp;
int loc,count=0;
printf("enter the location after which the number has to be inserted\n");
scanf("%d",&loc);
if(loc<=size)
{
temp=(node*)malloc(sizeof(node));
printf("enter the number to be inserted\n");
scanf("%d",&temp->data);
for(p=start;p!=NULL;p=p->ptr)
{
count++;
if(count==loc)
{
temp->ptr=p->ptr;
p->ptr=temp;
printf("new linked list is:");
for(p=start;p!=NULL;p=p->ptr)
printf("%d",p->data);
return(0);
}
else
{
printf("location is not found\n");
return(0);
}
}
}
return(0);
}

#include<iostream>
#include<conio.h>
#include<cassert>
using namespace std;
 
struct nodeType
{
       int info;
       nodeType *link;
};      
 
int main()
{
    int choice, num;
    nodeType *first, *last, *newNode, *current;
         cout<<"Enter numbers and press -999 to quit-->";
         cin>>num;
         first = 0; last = 0; current = 0; newNode = 0;
         while(num!=-999)
         {
                         newNode=new nodeType;
                         assert(newNode!=NULL);
                         newNode->info=num;
                         newNode->link=NULL;
                         if(first==NULL)
                         {
                                        first=newNode;
                                        last=newNode;
                         }
                         else
                         {
                             last->link=newNode;
                             last=newNode;
                         }
                         cin>>num;
         }
 
    cout<<"Enter 1.To insert at the end\n";
    cout<<"Enter 2.To insert at the beginning\n";
    cout<<"Enter 3.To insert in between\n";
    cin>>choice;
    if(choice==1)
    {
          cout<<"Enter number to insert at the end-->";
          cin>>num;
          newNode=new nodeType;
          assert(newNode!=NULL);
          newNode->info=num;
          newNode->link=NULL;
          if(first==NULL)
          {
                         first=newNode;
                         last=newNode;
          }
          else
          {
                         last->link=newNode;
                         last=newNode;
          }
    }
 
    else if(choice==2)
    {
         cout<<"Enter number to insert first-->";
          cin>>num;
          newNode=new nodeType;
          assert(newNode!=NULL);
          newNode->info=num;
          newNode->link=first;
          first=newNode;
    }
    else if(choice==3)
    {
          int loc, count=1;
          current=first;
          cout<<"Enter the location after which number has to be inserted-->";
          cin>>loc;
          cout<<"Enter the number-->";
          cin>>num;
          newNode=new nodeType;
          assert(newNode!=NULL);
          newNode->info=num;
          newNode->link=NULL;
          while(current!=NULL && count<loc)
          {
               current=current->link;
               count++;
          }
               if(count==loc)
               {
                             nodeType *temp;
                             temp=current->link;
                             current->link=newNode;
                             newNode->link=temp;
               }
    }
    else
    cerr<<"Enter correct input";
 
 
    current = first;
    while (current!=NULL)
    {
          cout<<current->info<<" ";
          current = current->link;
    }
    getch();
    return 0;
}