Singly linked list

#include<stdio.h>

#include<conio.h>

#include<alloc.h>

struct node

{

int data;

struct node *next;

};

void main()

{

struct node *head,*tp,*temp;

int ch,key,value;

clrscr();

head = NULL;

do

{

printf("1.Insert @ first\t 2.Insert @ last\t 3.Insert @ middle\n");

printf("4.Deletion\t 5.Display");

printf("\n\nEnter your choice:");

scanf("%d",&ch);

switch(ch)

{

case 1: {

            printf("\nenter a no to insert @ first:");

            temp=(struct node*)malloc(sizeof(struct node));

            scanf("%d",&value);

            temp->data=value;

            temp->next=NULL;

            if(head==NULL)

            {

            head=temp;

            }

            else

            {

            temp->next=head;

            head=temp;

            }}

            break;

case 2: {

            printf("\nenter a no to insert @ last:");

            temp=(struct node*)malloc(sizeof(struct node));

            scanf("%d",&value);

            temp->data=value;

            temp->next=NULL;

            if(head==NULL)

            {

             head=temp;

            }

            else

            {

             tp=head;

             while(tp->next!=NULL)

             {

             tp=tp->next;

             }

             tp->next=temp;

            }}

            break;

case 3: {

            printf("\nEnter a no to find:");

            scanf("%d",&key);

            printf("\nenter a no to insert @ middle:");

            temp=(struct node*)malloc(sizeof(struct node));

            scanf("%d",&value);

            temp->data=value;

            temp->next=NULL;

            if(head==NULL)

            head=temp;

            else

            {

             tp=head;

             while(tp!=NULL && tp->data!=key)

             tp=tp->next;

             if(tp!=NULL)

             {

             temp->next=tp->next;

             tp->next=temp;

             }

             else

             printf("\nElement not found...");

            }}

            break;

case 4: {

            printf("\nEnter a no to delete:");

            scanf("%d",&key);

            if(head==NULL)

            printf("\nlist is empty");

            else

            {

            tp=head;

            while(tp!=NULL && tp->data!=key)

            {

            temp=tp;

            tp=tp->next;

            }

            if(tp!=NULL)

            {

            if(tp==head)

            {

            head=head->next;

            free(tp);

            }

            else

            {

            temp->next=tp->next;

            free(tp);

            } }

            else

            printf("\nelement not found");

            }}

            break;

case 5: {

            if(head!=NULL)

            tp=head;

            while(tp!=NULL)

            {

            printf("%d\t",tp->data);

            tp=tp->next;

            }

            printf("\n");

            }break;

default:printf("\nenter correct choice");

            break;

}

}while(ch<=5);

getch();

}