C Program to Check Pronic Number

Posted in C Tutorial

Updated on Oct 27, 2024

By Mari Selvan

👁️ 90 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In the realm of programming, mathematical patterns and properties often become interesting challenges. One such intriguing concept is the "Pronic Number."

A pronic number, also known as a rectangular number, oblong number, or heteromecic number, is the product of two consecutive integers.

In this tutorial, we will explore a C program designed to check whether a given number is a pronic number or not.

📄 Example

Now, let's delve into the C code that checks whether a given number is a pronic number or not.

isPronic.c

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#include <stdio.h>
#include <math.h>

// Function to check if a number is a pronic number
int isPronic(int num) {
  int sqrtNum = sqrt(num);

  return (sqrtNum * (sqrtNum + 1) == num);
}

// Driver program
int main() {
  // Replace this value with your desired number
  int number = 12;

  // Check if the number is a pronic number
  if (isPronic(number)) {
    printf("%d is a pronic number.\n", number);
  } else {
    printf("%d is not a pronic number.\n", number);
  }

  return 0;
}

💻 Testing the Program

To test the program with different numbers, simply replace the value of number in the main function.

Output

12 is a pronic number.

Compile and run the program to check if the given number is a pronic number.

🧠 How the Program Works

The program defines a function isPronic that takes a number as input and returns 1 (true) if the number is a pronic number and 0 (false) otherwise.
Inside the function, it calculates the square root of the input number.
It checks whether the product of the square root and the square root incremented by 1 equals the input number. If yes, the number is a pronic number.
The driver program tests the function with a sample number and prints the result.

📏 Between the Given Range

Let's take a look at the C code that checks for pronic numbers in the range from 1 to 20.

isPronic.c

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#include <stdio.h>

// Function to check if a number is pronic
int isPronic(int num) {
  for (int i = 0; i <= num; ++i) {
    if (i * (i + 1) == num) {
      return 1; // Return 1 if the number is pronic
    }
  }
  return 0; // Return 0 if the number is not pronic
}

// Driver program
int main() {
  printf("Pronic Numbers in the range 1 to 20:\n");

  for (int i = 1; i <= 20; ++i) {
    if (isPronic(i)) {
      printf("%d ", i);
    }
  }

  printf("\n");

  return 0;
}

💻 Testing the Program

Output

Pronic Numbers in the range 1 to 20:
2 6 12 20

Compile and run the program to see the pronic numbers in the specified range.

🧠 How the Program Works

The program defines a function isPronic that checks whether a given number is a pronic number.
Inside the function, it uses a loop to iterate through numbers up to the given number, checking if the product of two consecutive integers equals the input number.
The main function tests the function for numbers in the range from 1 to 20 and prints the pronic numbers.

🧐 Understanding the Concept of Pronic Numbers

Before delving into the code, let's take a moment to understand the concept of pronic numbers.

A pronic number is a product of two consecutive integers, and it has applications in various mathematical and geometric contexts.

A pronic number, denoted by P_n, is a number of the form P_n=n × (n+1) where n is a non-negative integer. The sequence of pronic numbers starts as 0, 2, 6, 12, 20, and so on.

For example, let's take n = 3. The corresponding pronic number would be P₃ = 3x(3+1) = 12.