This code
prints all prime factors of a specified number in both multiplication and power
form. There are two separate functions to print in different forms.
The
explanation of code is given in the code in comments. The code may be improved
for large integers and performance.
Source Code:
#include <stdio.h>
#include <iostream>
using namespace std;
/* A function to print all prime
factors in multiplication form of a given number */
void PrimeFactorsInMultiplication(int number)
{
if (number <
1)
return;
//print the
input
cout
<< number << " =
";
// Print the
number of 2s that divide number
while (number % 2
== 0)
{
if (number ==
2)
cout << "2 ";
else
cout << "2 x ";
number = number / 2;
}
// number
must be odd. So we can skip
// one
element (Note i = i +2)
for (int i =
3; i*i <= number; i = i +
2)
{
// While i
divides n, print i and divide n
while (number%i == 0)
{
if (number ==
i)
cout << i;
else
cout << i << " x ";
number = number / i;
}
}
// the
condition is to handle the case when number is a prime number greater than 2
if (number >
2)
cout << number;
}
/* A function to print all prime
factors in power form of a given number*/
void PrimeFactorInPower(int number)
{
int __se,
count = 0;
//print the
input
cout
<< number << " =
";
for (__se
= 2; __se <= number; __se++)
{
//calc the
power of primes using a counter
while ((number%__se) ==
0)
{
number = number /
__se;
count++;
}
//if count
>=1 then print the prime with their power
if (count
!= 0)
{
cout << __se << "^" <<
count << "\t";
count = 0;
}
}
}
/* main function to test above
functions */
int main()
{
cout
<< "Prime Facotrs in multiplication
form:\n\n";
for (size_t i =
1000; i < 1010; i++)
{
PrimeFactorsInMultiplication(i);
cout << "\n";
}
cout
<< "\n\nPrime Facotrs in power
form:\n\n";
for (size_t i =
1000; i < 1010; i++)
{
PrimeFactorInPower(i);
cout << "\n";
}
getchar();
return 0;
}
Output:
