C Program to Display Factors of a Number

Introduction

Factors of a number in programming can be utilized to perform various tasks such as simplifying fractions, algorithm optimization, and in educational tools that demonstrate basic concepts of mathematics. A factor of a number refers to any integer which divides the given number without leaving a remainder.

In this article, you will learn how to create a C program to find factors of a number. This will include setting up the basic structure of a C program, implementing the logic to find and display factors, and running example scenarios to see the program in action.

Implementing the Factor Display Function

Setup the Basic C Program Structure

1. Start by including the necessary libraries and declare the main function:
   c Copy

   #include <stdio.h>
   
   int main() {
       // Program code will go here
       return 0;
   }
   

Create a Function to Find and Print Factors in C

1. Define a function that takes an integer as an argument and prints all its factors:

   c Copy

   void printFactors(int num) {
       printf("Factors of %d are: ", num);
       for (int i = 1; i <= num; ++i) {
           if (num % i == 0) {
               printf("%d ", i);
           }
       }
       printf("\n");
   }
   

   The function printFactors iterates from 1 to the number itself, checking if the number is divisible by each integer i. If the number is divisible (i.e., num % i == 0), i is printed as a factor.

Add Function Calls in the Main Program

1. Modify the main() function to prompt the user for a number and display its factors:

   c Copy

   int main() {
       int number;
       printf("Enter a number: ");
       scanf("%d", &number);
   
       printFactors(number);
   
       return 0;
   }
   

   This code obtains an integer from the user, then calls the printFactors() function to display the factors of the entered number.

Running Example Scenarios

Example 1: Finding Factors of a Small Number

1. Compile and run the program, then input 6:

   console Copy

   Enter a number: 6
   Factors of 6 are: 1 2 3 6
   

   In this example, the factors of 6 are 1, 2, 3, and 6 which the program correctly identifies and displays.

Example 2: Finding Factors of a Larger Number

1. Try a larger number, such as 36:

   console Copy

   Enter a number: 36
   Factors of 36 are: 1 2 3 4 6 9 12 18 36
   

   The program identifies all factors of 36 from 1 to 36, including divisor pairs that multiply to 36.

Conclusion

The C program for displaying factors of a number efficiently determines and prints all whole number divisors of any given number. This small project enhances your understanding of loops, conditionals, and basic input/output in C. Implementing such programs not only deepens your understanding of fundamental programming concepts but also gives practical insight into mathematical applications in programming, offering a methodical approach to problem-solving and debugging in software development.