Program to print factors of a number in pairs

Given a number n, the task of the programmer is to print the factors of the number in such a way that they occur in pairs. A pair signifies that the product of the pair should result in the number itself;

Examples:

Input : 24
Output : 1*24
         2*12
         3*8
         4*6

Input : 50
Output : 1*50
         2*25
         5*10

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

The simplest approach for this program is that we run a loop from 1 to the square root of N and print and print ‘i’ and ‘N%i’ if the number N is dividing ‘i’.

The mathematical reason why we run the loop till square root of N is given below:

If a*b = N where 1 < a ≤ b < N
N = ab ≥ a^2 ⇔ a^2 ≤ N ⇔ a ≤ √N

C++

// CPP program to print prime factors in 
// pairs. 
#include <iostream> 
using namespace std; 
  
void printPFsInPairs(int n) 
{ 
    for (int i = 1; i * i <= n; i++) 
        if (n % i == 0) 
            cout << i << "*" << n / i << endl; 
} 
  
// Driver code 
int main() 
{ 
    int n = 24; 
    printPFsInPairs(n); 
    return 0; 
} 

Java

// Java program to print prime factors in 
// pairs. 
public class GEE { 
  
    static void printPFsInPairs(int n) 
    { 
        for (int i = 1; i * i <= n; i++) 
            if (n % i == 0) 
                System.out.println(i + "*" + n / i); 
    } 
  
    // Driver code 
    public static void main(String[] args) 
    { 
  
        int n = 24; 
        printPFsInPairs(n); 
    } 
} 

C#

// C# program to print prime factors in 
// pairs. 
using System; 
public class GEE { 
  
    static void printPFsInPairs(int n) 
    { 
        for (int i = 1; i * i <= n; i++) 
            if (n % i == 0) 
                Console.Write(i + "*" + n / i + "\n"); 
    } 
  
    // Driver code 
    public static void Main() 
    { 
  
        int n = 24; 
        printPFsInPairs(n); 
    } 
} 

Python 3

# Python 3 program to print prime factors in 
# pairs. 
   
def printPFsInPairs(n):  
    for i in range(1, int(pow(n, 1 / 2))+1): 
        if n % i == 0: 
            print(str(i) +"*"+str(int(n / i)))    
   
# Driver code 
n = 24
printPFsInPairs(n) 

PHP

<?php 
// PHP program to print prime factors in 
// pairs. 
   
function printPFsInPairs($n)  
{ 
    for ($i = 1; $i*$i <= $n; $i++)  
        if ($n % $i == 0)  
            echo $i."*". $n / $i ."\n";     
} 
   
// Driver code 
$n = 24; 
printPFsInPairs($n); 
return 0; 
?> 

Output:

1*24
2*12
3*8
4*6

My Personal Notes

Smitha Dinesh Semwal

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