public class ProgramCorrectness {

	// Precondition: -10 <= x <= 7  
	public static int funcOne(int x) {
	    // uses an assertion to enforce the specified precondition in the method
	    assert (x >= -10 && x <= 7);
	    return (3 * x * x * x) - (2 * x * x) + 5;
	}

	// Preconditions: -5 <= x <= -2, 6 <= y <= 13   
	public static int funcTwo(int x, int y) {
	    return (3 * x * x * x) - (y * x * x) + 11;
	}

	// Postcondition: 0.25 <= return value <= 1.0
	public static double funcThree(double x) {

	    return 1.0 / x; 
	}
	
	// Precondition: x is an integer  
	public static int funcFour(int x) {

	    int retVal;
	    if (x % 2 == 0) {
	        retVal = x * x - x;
	    } else {
	        retVal = (x + x) * (x + x);
	    }
	    assert(retVal % 2 == 0);
	    return retVal;
	}

	// Precondition: x >= 1
	public static void funcFive(int x) {

	    int result = 1;
	    int i = 0;
	    do {
	        i++;
	        result = result * i;
	    } while (i < x);
	}

	// QUESTION: Does this correct swap the locals a and b? Why or why not?
	public static void funcSix(int a, int b) {

	    System.out.println("Before: a = " + a + " and b = " + b);
	    if (a < b) {
	        int r = a % b;
	        a = b;
	        b = r;
	    }
	    else {
	        int r = b;
	        b = a;
	        a = r;
	    }
	    System.out.println("After: a = " + a + " and b = " + b);
	}
	
	
	public static void main(String[] args){
		
		
	}

}