Calculating Power by Recursion in C++

Exercise:

Write a C++ program that uses recursive functions to calculate power.

Click Here to View the Solution:
#include <iostream>
using namespace std;
int power(int, int);
int main()
{
    int num, p, ans;
    cout << "Insert a positive number: ";
    cin >> num;
    cout << "Insert the power of the number: ";
    cin >> p;
    ans = power(num, p);            
    // pow(num,p) is a pre-defined function available in C++
    cout << num << "^" << p << " = " << ans;
    return 0;
}
int power(int num, int p)
{
    if (p != 0)
    return (num*power(num, p-1));
    else
    return 1;
}
Click Here to View the Output:
Insert a positive number: 3
Insert the power of the number: 4
3^4 = 81
Click Here to View the Explanation:
  • User is requested to enter a positive integer. It is stored as a variable num. The user is requested to enter the power and it is saved as p.
  • The pow () function is used calculate the power of num and the answer is stored in a variable as ans.
  • A recursive function power ( ) is created.
  • The recursive function is called in the main () function.
  • Output is displayed on the screen.