Power of a Number using Recursion in Java

June 2, 2022

Power of a Number using Recursion in Java

Here, in this page we will discuss the program to find power of a number using recursion in java programming language. We are given with two integers values base and power respectively. We need to print the value representing the base raise to its power. We will design the program using recursion and also discuss the approach using iteration as well.

Example :

Input : 5 3
Output : 125
Explanation : 5³ = 125

Method 1 (Using Recursion):

Create a recursive function say power(int base, int x)
Base condition : if(x==0) return 1.
Otherwise, return (base* power(base, x-1))

Time and Space Complexity Time Complexity : O(x), x denotes the power. Space Complexity : O(1)

Java Code

Run

public class Main
{
  public static void main (String[]args)
  {
    int base = 5, x = 3;
    System.out.println ("Required Power is " + power (base, x));
  }
  //Recursive Function
  static int power (int base, int x)
  {
    if (x == 0)     //Base Condition
      return 1;
    return (base * power (base, x - 1));
  }
}

Output

Required Power is 125

Method 2 (Using Loop):

Create a function say power(int base, int x), that will return the integer value denoting the base^x.
Create a variable say result = 1, that hold the base^x.
Run a while loop that will terminate when x becomes 0.
Inside the loop set result = result * base.
After complete iteration return result.

Time and Space Complexity Time Complexity : O(x), x denotes the power. Space Complexity : O(1)

Run

class Main {
    public static void main(String[] args) {
        int base = 5, x = 3;
        System.out.println("Required Power is " + power(base, x));
    }
    static int power(int base, int x) {
        int result = 1;
        while (x > 0) {
            result *= base;
            x--;
        }
        return result;
    }
}

Output

Required Power is 125