#include
#include
typedef struct node // structure node
{
int info; // a information that is to be stored
struct node *next; // create a next name pointer which will point to node type
}node_t; // node_t object is created
node_t *first,*rear,*printing;
// first is for storing first information pointer
// rear is to store where we have last stored the information
// printing is to track while printing.
void createlist(); // it create a empty list
void insert_element_at_beg(int);
// above funtion will create a new node and insert that into list
// below function will create a new node and insert that into list
void insert_element_at_end(int);
// below function will create a new node and insert it after
// at specific node if found else print node not found
void insert_element_at_mid();
void print_list(); // it will print the list
void main()
{
int info,choice,after;
clrscr();
// create list at first
createlist();
// loop till user wants to exit
do
{ // ask user for choices
printf("Enter your choice\n\n");
printf("Press 1 to Enter the Number at the begining\n");
printf("Press 2 to Enter the Number at the end\n");
printf("Press 3 to Enter the Number at mid\n");
printf("Press 4 to Print the list\n");
printf("Press 5 to exit\n");
scanf("%d",&choice);
// if one call insert_element()
if(choice==1)
{
printf(" \n Enter the element");
scanf("%d",&info);
insert_element_at_beg(info);
}
else if(choice==2){
printf("\n Enter the element");
scanf("%d",&info);
insert_element_at_end(info);
}
else if(choice==3){
insert_element_at_mid();
}
else if(choice==4){
print_list(); // it will print the list
printf("\n");
}
}
while(choice!=5); // if choice is 2 break the loop
getch();
}
void createlist()
{
node_t *createlist=malloc(sizeof(node_t)); // create a new node
// intialize everyting with null
createlist->next=NULL;
createlist->info=NULL;
// initialize first and rear with the first node created
first=createlist;
rear=createlist;
}
void insert_element_at_beg(int element)
{
node_t *new_node=malloc(sizeof(node_t)); // create a new node
// check if list is empty
// if yes then enter the first element
if(first->info==NULL)
{
first->info=element;
}
// if not first node then
// enter the info in newly created node and
// point its next to our last created node.
// and make our rear pointing to newly created node.
else
{
new_node->info=element;
new_node->next=rear;
rear=new_node;
}
}
void insert_element_at_end(int element){
node_t *new_node=malloc(sizeof(node_t)); // create a new node
// check if list is empty
// if yes then enter the first element
if(first->info==NULL)
{
first->info=element;
}
// if not first node then
// enter the info in newly created node and
// point its next to our last created node.
// and make our rear pointing to newly created node.
else
{
new_node->info=element;
new_node->next=NULL;
first->next=new_node;
first=new_node;
}
}
void insert_element_at_mid(){
node_t *new_node=malloc(sizeof(node_t)); // create a new node
int element,afterv;
char choice1;
if(first->info==NULL)
{
printf("\nList is empty. Add some numbers first\n");
}
else{
printf("\n Enter the element after which you want to add\n");
scanf("%d",&afterv);
printf("\n Enter the element which you wnat to add\n");
scanf("%d",&element);
printing=rear;
// loop to find the element after which we have to enter the new number
while(printing->info!=afterv){
printing=printing->next;
if(printing==NULL) // if not element not found then break the loop
break;
}
if(printing==NULL){
printf("Element Not Found");
}
else{ // if found than add the node.
new_node->info=element;
new_node->next=printing->next;
printing->next=new_node;
}
}
}
// prints the whole list
void print_list()
{
printing=rear; // intializes the printing
// while loop -- until a node with next=null is not found
while(printing!=NULL)
{ if(printing->next==NULL && printing->info==NULL){
printf("List is Empty");
}
printf("%d ",printing->info);
printing=printing->next;
}
}