C Exercises: Check whether a given number is an armstrong number or not

C For Loop: Exercise-29 with Solution

Write a C program to check whether a given number is an Armstrong number or not.

When the sum of the cube of the individual digits of a number is equal to that number, the number is called Armstrong number. For Example 153 is an Armstrong number because 153 = 1³+5³+3³.

Test Data :
Input a number: 153
Expected Output :
153 is an Armstrong number.

Visual Presentation:

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Sample Solution:

C Code:

#include <stdio.h> // Include the standard input/output header file.

int main() {
    int num, r, sum = 0, temp; // Declare variables for the input number, remainder, sum, and a temporary variable.

    printf("Input a number: "); // Prompt the user to input a number.
    scanf("%d", &num); // Read the number from the user.

    temp = num; // Save the original number in a temporary variable.

    while (num != 0) { // Start a loop to extract digits from the number.
        r = num % 10; // Get the last digit of the number.
        sum = sum + (r * r * r); // Calculate the sum of cubes of each digit.
        num = num / 10; // Move to the next digit.
    }

    if (sum == temp) // If the sum of cubes of digits is equal to the original number.
        printf("%d is an Armstrong number.\n", temp); // Print that it's an Armstrong number.
    else
        printf("%d is not an Armstrong number.\n", temp); // Otherwise, print that it's not an Armstrong number.

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

Sample Output:

Input  a number: 153                                                                                          
153 is an Armstrong number.   

Flowchart:

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