// MathStuff
// Functional class for practice exam 2
// Kevin Bierre

public class MathStuff {
	// this method calculates the factorial of a number
	// and returns it to the calling routine
	public int factorial(int num) {
		// loop to calculate the factorial value
		boolean negative = false;
		if(num < 0) {
			negative = true;	 // flag as negative value
			num = Math.abs(num); // get positive value
		}
		int result = 1;
		for(int i = 1; i <= num; i++) {
			result *= i;
		}
		
		// fix negative value
		if(negative) {
			result *= (-1); // multiply by -1
		}
		
		// return result
		return result;
	}
	
	// this method calculates the summation of a number
	// and returns it to the calling routine
	public int summation(int num) {
		// loop to calculate the summation value
		boolean negative = false;
		if(num < 0) {
			negative = true;	 // flag as negative value
			num = Math.abs(num); // get positive value
		}
		int result = 0;
		for(int i = 0; i <= num; i++) {
			result += i;
		}
		
		// fix negative value
		if(negative) {
			result *= (-1); // multiply by -1
		}
		
		// return result
		return result;
	}
}