import static Helpers320.UtilsIan.*;

class StackDiagram {
    
    public static void main( String... argv ) {
        testAll();
        System.out.printf("This program verifies whether 5 to the 300th power is bigger than 0.\n");
        int x = 5;
        int y = 300;
        String report = "Yes!";
        boolean overflow;

        if (power(x,y) >= 0) {
            System.out.printf("%s\n",report);
            overflow = false;
            }
        else {
            System.out.printf( "It's not!  Hmmm; overflow?\n" );
            overflow = true;
            }
        System.exit(overflow ? 1 : 0);  // indicate an error, to the shell / caller.
        }


    // Return a^b.
    //
    static int power(int a, int b) {
        int product = 1;
        while (b!=0) {
            product = multiply(product, a);
            b--;
            }
        return product;
        }


    // Return x*y.
    //
    static int multiply(int x, int y) {
        return x*y;
        }
    
    
    static void testAll() {
        assertAssertionsEnabled();
        testMultiply();
        testPower();
        }

    static void testMultiply() {
        System.out.printf("testMultiply: ");
        assertEquals( multiply(0,0), 0);
        assertEquals( multiply(0,3), 0);
        assertEquals( multiply(3,0), 0);
        
        assertEquals( multiply(1,1), 1);
        assertEquals( multiply(1,3), 3);
        assertEquals( multiply(3,1), 3);
        
        assertEquals( multiply(3,2),  6 );
        assertEquals( multiply(3,-2), -6 );
        assertEquals( multiply(-3,2), -6 );
        assertEquals( multiply(-3,-2),  6 );
        assertEquals( multiply(200,75), 15000 );
        System.out.printf("done\n");
        }
    
    static void testPower() {
        System.out.printf("testPower: ");
        //assertEquals( power(0,0), 1 );
        assertEquals( power(0,1), 0 );
        assertEquals( power(1,0), 1 );
        
        assertEquals( power(0,3), 0 );
        assertEquals( power(3,0), 1 );
        assertEquals( power(1,1), 1 );
        assertEquals( power(1,3), 1 );
        assertEquals( power(3,1), 3 );
        
        assertEquals( power( 3,2),    9 );
        assertEquals( power( 3,3),   27 );
        assertEquals( power(-3,2),    9 );
        assertEquals( power(-3,3),  -27 );
        assertEquals( power(2,10), 1024 );
        assertEquals( power(10,9), 1000000000 );
        System.out.printf("done\n");
        }
    
    
    }

/**
 * @author ibarland
 * @version 2025-Jan-20
 * 
 * @license CC-BY -- share/adapt this file freely, but include attribution, thx.
 *     https://creativecommons.org/licenses/by/4.0/ 
 *     https://creativecommons.org/licenses/by/4.0/legalcode 
 * Including a link to the *original* file satisifies "appropriate attribution".
 */