C Program to Calculate Power of a Number Using Recursion

Introduction

Calculating the power of a number involves raising a base number to an exponent. For example, ( 2^3 = 2 \times 2 \times 2 = 8 ). This guide will show you how to write a C program to calculate the power of a number using recursion.

Example:

• Input: base = 2, exponent = 3
• Output: 8 (since ( 2^3 = 8 ))

Problem Statement

Create a C program that:

• Takes a base number and an exponent as input from the user.
• Uses a recursive function to calculate the power of the base raised to the exponent.
• Displays the result.

Solution Steps

1. Include the Standard Input-Output Library: Use #include <stdio.h> for standard input-output functions.
2. Write the Recursive Function: Define a recursive function that calculates the power of a number.
3. Write the Main Function: Define the main function to take user input, call the recursive function, and display the result.
4. Input the Base and Exponent: Use scanf to take input from the user for the base and exponent.
5. Call the Recursive Function: Pass the base and exponent to the recursive function to calculate the power.
6. Display the Result: Use printf to display the calculated power.

C Program to Calculate Power of a Number Using Recursion

#include <stdio.h>

// Step 2: Define the recursive function to calculate power
int power(int base, int exponent) {
    if (exponent == 0) {
        return 1;  // Base case: Any number raised to the power of 0 is 1
    } else {
        return base * power(base, exponent - 1);  // Recursive case
    }
}

int main() {
    // Step 3: Declare variables to hold the base and exponent
    int base, exponent;

    // Step 4: Prompt the user to enter the base and exponent
    printf("Enter base: ");
    scanf("%d", &base);
    printf("Enter exponent: ");
    scanf("%d", &exponent);

    // Step 5: Call the recursive function to calculate the power
    int result = power(base, exponent);

    // Step 6: Display the result
    printf("%d^%d = %d\n", base, exponent, result);

    return 0;  // Return 0 to indicate successful execution
}

Explanation

Step 2: Define the Recursive Function

• The power function takes two integers base and exponent as input.
• Base Case: If the exponent is 0, the function returns 1 (since any number raised to the power of 0 is 1).
• Recursive Case: If the exponent is greater than 0, the function returns base * power(base, exponent - 1), recursively calling itself with the exponent decremented by 1.

Step 3: Declare Variables

• The variables base and exponent store the input values for the base and exponent.

Step 4: Input the Base and Exponent

• The program prompts the user to enter the base and exponent using scanf.

Step 5: Call the Recursive Function

• The program calls the power function with base and exponent as arguments and stores the result in the variable result.

Step 6: Display the Result

• The program uses printf to display the calculated power.

Return 0

• The return 0; statement indicates that the program executed successfully.

Output Example

Example 1:

Enter base: 2
Enter exponent: 3
2^3 = 8

Example 2:

Enter base: 5
Enter exponent: 4
5^4 = 625

Example 3:

Enter base: 7
Enter exponent: 0
7^0 = 1

Conclusion

This C program demonstrates how to calculate the power of a number using a recursive function. It covers basic concepts such as recursion, base cases, and user input, making it a useful example for beginners learning C programming.