Write a C program to implement Insertion and Deletion (from beginning, intermediate and end) by using Linked List.

Program:-

#include<stdio.h>
#include<malloc.h>
struct node{ int info; struct node *next;} *temp, *start=NULL, *ptr, *t;
void in(); void inbeg(); void inend(); void inint();
void del(); void delend(); void delbeg(); void delint();
void dis();

void in() //Insert function
{ int cho;
  printf("\n1.INSERT AT END\n2.INSERT AT BEGINNING\n3.INSERT AT INTERMIDIATE\n");
  printf("Enter your choice:");
  scanf("%d",&cho);
  switch(cho)
   {case 1: inend(); printf("\n"); break;
    case 2: inbeg(); printf("\n"); break;
 case 3: inint(); printf("\n"); break;
 default:printf("Wrong input\n");
   }
}

void del() //Delete fuction
{ int cho;
  printf("\n1.DELETE AT END\n2.DELETE AT BEGINNING\n3.DELETE AT INTERMIDIATE\n");
  printf("Enter your choice:");
  scanf("%d",&cho);
  switch(cho)
   {case 1: delend();break;
    case 2: delbeg();break;
 case 3: delint();break;
 default:printf("Wrong input\n");
   }
}

void dis() //Display function
{
  ptr=start;
  printf("Your elements are:-\n");
  while(ptr!=NULL){ printf("%d ",ptr->info); ptr=ptr->next; }
  printf("\n");
}

void delbeg() //Delete from beginning
{ ptr=start->next; free(start); start=ptr; }
void delint() //Delete from intermediate
{ int i,loc;
  printf("Enter location:"); scanf("%d",&loc);
  for(i=0,ptr=start;i<loc-2;i++){ ptr=ptr->next; }
  t=ptr->next; ptr->next=t->next; free(t);
}
void delend() //Delete from end
{ ptr=start; while(ptr!=temp){ptr=ptr->next;} ptr->next=NULL; free(temp); temp=ptr; }


void inbeg() //Insert from beginning
{
   temp=(struct node*)malloc(sizeof(struct node));
   printf("Enter item:"); scanf("%d",&temp->info);
   if(start==NULL){ start=ptr=temp; ptr->next=NULL; }
 else{ temp->next=start; start=temp; }
}
void inint() //Insert from intermediate
{   int i,loc;
    printf("Enter location:"); scanf("%d",&loc);
   temp=(struct node*)malloc(sizeof(struct node));
   printf("Enter item:"); scanf("%d",&temp->info);
   for(i=0,ptr=start;i<loc-2;i++){ ptr=ptr->next; }
   temp->next=ptr->next; ptr->next=temp;
}
void inend() //Insert from end
{
   temp=(struct node*)malloc(sizeof(struct node));
   printf("Enter item:"); scanf("%d",&temp->info);
   if(start==NULL){ start=ptr=temp; ptr->next=NULL; }
 else{ ptr->next=temp; ptr=temp; ptr->next=NULL; }
}

//This program is Developed by MONISH KUMAR BAIRAGI

int main()
{ int cho=123;
  while(cho<4||cho==123)
  {printf("1.INSERT\n2.DELETE\n3.DISPLAY\n4.EXIT\n");
   printf("Enter your choice:");
   scanf("%d",&cho);
   switch(cho)
   {case 1: in(); printf("\n"); break;
    case 2: del(); printf("\n"); break;
 case 3: dis(); printf("\n"); break;
 default:printf("\nThank You.\nHave a Nice day.\n");
   }
  }
 return(0);
}

Output:-

1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter your choice:1

1.INSERT AT END
2.INSERT AT BEGINNING
3.INSERT AT INTERMIDIATE
Enter your choice:1
Enter item:10


1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter your choice:1

1.INSERT AT END
2.INSERT AT BEGINNING
3.INSERT AT INTERMIDIATE
Enter your choice:1
Enter item:100


1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter your choice:1

1.INSERT AT END
2.INSERT AT BEGINNING
3.INSERT AT INTERMIDIATE
Enter your choice:1
Enter item:20


1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter your choice:1

1.INSERT AT END
2.INSERT AT BEGINNING
3.INSERT AT INTERMIDIATE
Enter your choice:1
Enter item:30


1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter your choice:3
Your elements are:-
10 100 20 30

1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter your choice:2

1.DELETE AT END
2.DELETE AT BEGINNING
3.DELETE AT INTERMIDIATE
Enter your choice:2

1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter your choice:3
Your elements are:-
100 20 30

1.INSERT
2.DELETE
3.DISPLAY
4.EXIT
Enter your choice:4

Thank You.
Have a Nice day.