Implement the unsorted single linked list as we did in the c

Implement the unsorted single linked list as we did in the class and implement the following operations: 1.DeletelastDuplicat(): For any element in the linked list, if there are multiple copies (> = 2 copies), delete the last copy. DeleteSecondlastDuplicat(): For any element in the linked list, if there are multiple copies (> = 2 copies), delete the second last copy Test your program with the following operations: a)insert 5 b)Insert 7 c)Insert 11 d)Insert 5 e)Insert f) Insert 5 g) Print out the list h) Delete the last duplicate of 5 i)Print out the list i) Delete the last duplicate of 11 k) Print out the list I) Insert 11 m) Insert 7 n) Print out the list O) Delete the second last duplicate of 5 p) Print out the list q) Delete the second last duplicate of 7 r) Print out the list

Solution

#include<iostream>
#include<cstdio>
#include<cstdlib>
using namespace std;
struct node
{
int data;
struct node *next;
}*start;
class LinkedList
{
public:
node* create_node(int);
void insert_begin();
void insert_pos();
void insert_last();
void delete_pos(int);
void delete_lastdup();
void delete_seclast();
int search(int);
void display();
int get_count(int);
LinkedList()
{
start = NULL;
}
};
int main()
{
int choice, pos, value, res=0;
LinkedList sl;
start = NULL;
while (1)
{
cout<<endl<<\"Operations on singly linked list\"<<endl;
cout<<\"1.Insert Node at beginning\"<<endl;
cout<<\"2.Insert node at last\"<<endl;
cout<<\"3.Insert node at position\"<<endl;
cout<<\"4.Delete a Particular Node\"<<endl;
cout<<\"5.Search Element\"<<endl;
cout<<\"6.Display Linked List\"<<endl;
cout<<\"7.Delete last duplicate\"<<endl;
cout<<\"8.Delete second last duplicate\"<<endl;
cout<<\"9.Exit \"<<endl;
cout<<\"Enter your choice : \";
cin>>choice;
switch(choice)
{
case 1:
cout<<\"Inserting Node at Beginning: \"<<endl;
sl.insert_begin();
cout<<endl;
break;
case 2:
cout<<\"Inserting Node at Last: \"<<endl;
sl.insert_last();
cout<<endl;
break;
case 3:
cout<<\"Inserting Node at a given position:\"<<endl;
sl.insert_pos();
cout<<endl;
break;
case 4:
cout<<\"Delete a particular node: \"<<endl;
cout<<\"Enter the position of value to be deleted: \";
cin>>pos;
sl.delete_pos(pos);
break;
case 5:
cout<<\"Search element in Link List: \"<<endl;
cout<<\"Enter the value to be searched: \";
cin>>value;
res=sl.search(value);
cout<<\"Element \"<<value<<\" is found at position \"<<res<<endl;
cout<<endl;
break;
case 6:
cout<<\"Display elements of link list\"<<endl;
sl.display();
cout<<endl;
break;
case 7:
sl.delete_lastdup();
cout<<endl;
break;
case 8:
sl.delete_seclast();
cout<<endl;
break;
case 9:
exit(1);
break;
default:
cout<<\"Enter valid choice..!!\"<<endl;
}
}
return 0;
}
//function to create node
node *LinkedList::create_node(int value)
{
struct node *temp;
temp = new(struct node);
if (temp == NULL)
{
return 0;
}
else
{
temp->data = value;
temp->next = NULL;   
return temp;
}
}

//function to insert element at beginning
void LinkedList::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\"<<endl;
}

int LinkedList::get_count(int value)
{
int count=0;
struct node *s;
s = start;
while (s->next != NULL)
{   
if(s->data == value)
count++;
s = s->next;
}
return count;
}

//function to insert node at last
void LinkedList::insert_last()
{
int value;
cout<<\"Enter the value to be inserted: \";
cin>>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\"<<endl;
}
//function to insert node at position
void LinkedList::insert_pos()
{
int value, pos, counter = 0;
cout<<\"Enter the value to be inserted: \";
cin>>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\"<<endl;
}
}

//delete last duplicate element
void LinkedList::delete_lastdup()
{
int value,c=0,pos=0;
cout<<\"Enter element to be deleted:\";
cin>>value;
c=get_count(value);
if(c<2)
{
cout<<\"duplicate does not exist\"<<endl;
return;
}
else
{
pos=search(value);
delete_pos(pos);
}
}

//delete second last duplicate element
void LinkedList::delete_seclast()
{
int value,c=0,pos=0,res=0,f=0,x;
cout<<\"Enter element to be deleted:\";
cin>>value;
c=get_count(value);
x=c-1;
if(c<2)
{
cout<<\"duplicate does not exist\"<<endl;
return;
}
else
{
struct node *s;
s = start;
while (s != NULL)
{
pos++;
if (s->data == value)
{
f++;
res=pos;
  
if(f==x)
break;
  
}
s = s->next;
}
delete_pos(res);
}
}

//delete element at position
void LinkedList::delete_pos(int pos)
{
int i, counter = 0;
if (start == NULL)
{
cout<<\"List is empty\"<<endl;
return;
}
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\"<<endl;
}
free(s);
cout<<\"Element Deleted\"<<endl;
}
}

//function to search element
int LinkedList::search(int value)
{
int pos = 0,res=0;
bool flag = false;
if (start == NULL)
{
cout<<\"Empty list..!!\"<<endl;
return pos;
}

struct node *s;
s = start;
while (s != NULL)
{
pos++;
if (s->data == value)
{
flag = true;
res=pos;
}
s = s->next;
}
if (!flag)
cout<<\"Element \"<<value<<\" not found in the list\"<<endl;
return res;
}

//function to display element
void LinkedList::display()
{
struct node *temp;
if (start == NULL)
{
cout<<\"The List is Empty\"<<endl;
return;
}
temp = start;
cout<<\"Elements of list are: \"<<endl;
while (temp != NULL)
{
cout<<temp->data<<\"->\";
temp = temp->next;
}
cout<<\"NULL\"<<endl;
}