Singly linked list in c++

This C++ Program Implements Singly Linked List.
Here is source code of the C++ Program to Implement Singly Linked List. The C++ program is successfully compiled and run on a Linux system. The program output is also shown below.

/*
* C++ Program to Implement Singly Linked List
*/
#include
#include
#include
using namespace std;
/*
* Node Declaration
*/
struct node
{
int info;
struct node *next;
}*start;

/*
* Class Declaration
*/
class single_llist
{
public:
node* create_node(int);
void insert_begin();
void insert_pos();
void insert_last();
void delete_pos();
void sort();
void search();
void update();
void reverse();
void display();
single_llist()
{
start = NULL;
}
};

/*
* Main :contains menu
*/
main()
{
int choice, nodes, element, position, i;
single_llist sl;
start = NULL;
while (1)
{
cout<>choice;
switch(choice)
{
case 1:
cout<<"Inserting Node at Beginning: "<info = value;
temp->next = NULL;
return temp;
}
}

/*
* Inserting element in beginning
*/
void single_llist::insert_begin()
{
int value;
cout<<"Enter the value to be inserted: "; cin>>value;
struct node *temp, *p;
temp = create_node(value);
if (start == NULL)
{
start = temp;
start->next = NULL;
}
else
{
p = start;
start = temp;
start->next = p;
}
cout<<"Element Inserted at beginning"<>value;
struct node *temp, *s;
temp = create_node(value);
s = start;
while (s->next != NULL)
{
s = s->next;
}
temp->next = NULL;
s->next = temp;
cout<<"Element Inserted at last"<>value;
struct node *temp, *s, *ptr;
temp = create_node(value);
cout<<"Enter the postion at which node to be inserted: "; cin>>pos;
int i;
s = start;
while (s != NULL)
{
s = s->next;
counter++;
}
if (pos == 1)
{
if (start == NULL)
{
start = temp;
start->next = NULL;
}
else
{
ptr = start;
start = temp;
start->next = ptr;
}
}
else if (pos > 1 && pos <= counter) { s = start; for (i = 1; i < pos; i++) { ptr = s; s = s->next;
}
ptr->next = temp;
temp->next = s;
}
else
{
cout<<"Positon out of range"<next;s !=NULL;s = s->next)
{
if (ptr->info > s->info)
{
value = ptr->info;
ptr->info = s->info;
s->info = value;
}
}
ptr = ptr->next;
}
}

/*
* Delete element at a given position
*/
void single_llist::delete_pos()
{
int pos, i, counter = 0;
if (start == NULL)
{
cout<<"List is empty"<>pos;
struct node *s, *ptr;
s = start;
if (pos == 1)
{
start = s->next;
}
else
{
while (s != NULL)
{
s = s->next;
counter++;
}
if (pos > 0 && pos <= counter) { s = start; for (i = 1;i < pos;i++) { ptr = s; s = s->next;
}
ptr->next = s->next;
}
else
{
cout<<"Position out of range"<>pos;
cout<<"Enter the new value: "; cin>>value;
struct node *s, *ptr;
s = start;
if (pos == 1)
{
start->info = value;
}
else
{
for (i = 0;i < pos - 1;i++) { if (s == NULL) { cout<<"There are less than "<next;
}
s->info = value;
}
cout<<"Node Updated"<>value;
struct node *s;
s = start;
while (s != NULL)
{
pos++;
if (s->info == value)
{
flag = true;
cout<<"Element "<next;
}
if (!flag)
cout<<"Element "<next == NULL)
{
return;
}
ptr1 = start;
ptr2 = ptr1->next;
ptr3 = ptr2->next;
ptr1->next = NULL;
ptr2->next = ptr1;
while (ptr3 != NULL)
{
ptr1 = ptr2;
ptr2 = ptr3;
ptr3 = ptr3->next;
ptr2->next = ptr1;
}
start = ptr2;
}

/*
* Display Elements of a link list
*/
void single_llist::display()
{
struct node *temp;
if (start == NULL)
{
cout<<"The List is Empty"<info<<"->“;
temp = temp->next;
}
cout<<"NULL"<100->NULL

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