Printing Linked List Recursively in C++

Printing Linked List Recursively in C++ Program is given below:

// Printing Linked List Recursively in C++
// Linked List is created by inserting at head and then printing recursively.
#include <iostream>
using namespace std;

Printing Linked List in Reverse Order Recursively in C++

Printing Linked List in Reverse Order Recursively in C++ Program is given below:

// Printing Linked List in Reverse Order Recursively in C++
// Insertion at head is done in the following program
#include <iostream>
using namespace std;

////////////////////////////////////////////////////////////////
struct link                           //one element of list
{
int data;                          //data item
link* next;                        //pointer to next link
};
////////////////////////////////////////////////////////////////
class linklist                        //a list of links
{
private:
link* first;                    //pointer to first link also known as head.
public:
linklist()                      //no-argument constructor
{ first = NULL; }            //no first link
link* getHead(){ return first; }
void additem(int d);            //add data item (one link)
void displayRecursivelyReversed(link* current);                 //display all links in REVERSE ORDER.
};
//-------------------------------------------------------------void
void linklist::additem(int d)         //add data item
{
link *newLink = new link;
newLink->data = d;
//insert at head
newLink->next = first;
first = newLink;
}
//-------------------------------------------------------------void
void linklist::displayRecursivelyReversed(link* current)              //display all links
{
if (current != NULL){
//move to next node.
displayRecursively(current->next);
cout << current->data << endl;
}

}
////////////////////////////////////////////////////////////////
int main()
{
linklist li;       //make linked list
li.additem(25);    //add four items to list
li.additem(36);
li.additem(49);
li.additem(64);
li.displayRecursivelyReversed(li.getHead());      //display entire list
return 0;
}

Pi Recursion C++

The value of π can be determined by the series equation
π=4∗(1-1/3+1/5−1/7+1/9−1/11+1/13…)
Write a program that prompts the user to enter a positive odd number n and uses recursion to approximate the value of π using the given formula including term up through 1/n.
Solution:

Recursive function to search through array

Recursive function to search through array.

Write a program that asks the user to enter 10 integers, stores these numbers in an array. The program should ask if the user would like to search an element in the array, in which case the program should then prompt the user to enter the number to look for. Use a recursive function find( int index, int target, int array[] ) that does sequential search for a target in this array. Display an appropriate message to the user after searching the element.

Solution: