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.

Sample Solution:

C Code:

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

void 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.

    for(temp=num;num!=0;num=num/10){ // 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.
    }

    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.
}

Sample Output:

Input  a number: 153                                                                                          
153 is an Armstrong number.   

Flowchart:

C Programming Code Editor:

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