CS 111- Fall 2012

Solutions to Exam 2

1. B
2. A
3. C
4. D
5. B
6. D
7. A
8. C
9. A
10. B
11. C
12. C
13. A
14. D
15. C
16. A
17. C
18. D
19. B
20. C
21. public static Picture q21 (Picture p)
    {
    int wid = p.getWidth();
    int hgt = p.getHeight();
    
    int x;
    int y;
    
    for ( x = 0 ; x < wid ; x = x + 1 ) // loop for each column
    {
    for ( y = 0 ; y < hgt ; y = y + 1 ) // loop for each pixel in the column
    {
    Pixel pix = p.getPixel (x, y); // access the pixel
    
    // access the color valuesat the pixel
    int red = pix.getRed();
    int green = pix.getGreen();
    int blue = pix.getBlue();
    
    // modify the color values
    int grayAmount = (red + green + blue ) / 3;
    
    if ( grayAmount < 64 )
    {
    pix.setColor ( Color.MAGENTA );
    }
    else if ( grayAmount < 128 )
    {
    pix.setColor ( Color.RED );
    }
    else if ( grayAmount < 192 )
    {
    pix.setColor ( Color.ORANGE );
    }
    else
    {
    pix.setColor ( Color.YELLOW );
    }
    }
    }
    
    return p;
    } // end of q21
22. public static Picture q22 (Picture p)
    {
    int wid = p.getWidth();
    int hgt = p.getHeight();
    
    Picture p2 = new Picture (wid, hgt * 2);
    
    int x;
    int y;
    Color c;
    
    for ( x = 0 ; x < wid ; x = x + 1 ) // loop for each column
    {
    for ( y = 0 ; y < hgt ; y = y + 1 ) // loop for each pixel in the column
    {
    Pixel pix = p.getPixel (x, y); // access the pixel
    c = pix.getColor();
    
    Pixel pix2 = p2.getPixel (x, y); // access the pixel
    pix2.setColor(c);
    pix2 = p2.getPixel (x, y + hgt); // access the pixel
    pix2.setColor(c);
    }
    }
    
    return p2;
    } // end of q22

• Exam2.java: Java program containing the code for both Q21 and Q22