# Visual C++ - Getting Prime Factors of a Number

Given a number, we can find out what would be the prime factors of  the number. But it is not easy to find out since we have to go through couple of iteratons.

Prime Factor For 9360 = 13 *  5 *  3 *  3 *  2 *  2 *  2 *  2

Note that all the numbers 13, 5, 3, 2 are prime numbers.

## Source Code

#include <stdio.h>

#include <tchar.h>

#include <iostream>

#define MAX_SIZE 15000

{

bool bPrime = true;

int factor = num / 2;

for(int i = 2; i <= factor; i++)

{

if( (num % i) == 0)

bPrime = false;

}

return bPrime;

}

{

int idx = 0;

for(int i = 2; i <= max; i++)

{

arr[idx++] = i;

}

return idx;

}

int GetPrimeFactors(int num, int *arrResult)

{

int idx = 0;

int arr[MAX_SIZE];

while(1)

{

{

arrResult[idx++] = num;

return idx;

}

for(int i = count - 1; i >= 0; i--)

{

if( (num % arr[i]) == 0)

{

arrResult[idx++] = arr[i];

num = num / arr[i];

break;

}

}

}

return idx;

}

int main()

{

int arr1[MAX_SIZE];

int num1;

std::cout << "Enter a Number: ";

std::cin >> num1;

int count = GetPrimeFactors(num1, arr1);

std::cout << "\nPrime Factors For " << num1 << " =";

for(int i = 0; i < count; i++)

{

std::cout << " " << arr1[i];

if(i != count - 1)

std::cout << " * ";

}

std::cout << "\n\n";

return 0;

}

## Output

Enter a Number: 9360

Prime Factors For 9360 = 13 *  5 *  3 *  3 *  2 *  2 *  2 *  2

Press any key to continue . . .

Enter a Number: 48125

Prime Factors For 48125 = 11 *  7 *  5 *  5 *  5 *  5

Press any key to continue . . .