NPR

This algorithm finds all possible rearrangement of the element i.e all the possible permutation value.

• C#
• VB.Net
• C
• C++
• PHP

									private static long Factorial(int number)
{
	if (number < 0)
		return -1; //Error

	long result = 1;

	for (int i = 1; i <= number; ++i)
		result *= i;

	return result;
}

public static long NPR(int n, int r)
{
	return Factorial(n) / Factorial(n - r);
}
								

Example

									long npr = NPR(5, 2);
								

Output

									20