These puzzles involve simple loops. Of course, "simple" is a relative term . . .
[M-21]Write a main() program that
prints an ASCII-art version of a pine tree:
...........*........... ..........***.......... .........*****......... ........*******........ .......*********....... ......***********...... .....*************..... ....***************.... ...*****************... ..*******************.. .*********************. *********************** ..........***.......... ..........***.......... ..........***.......... ..........***..........
You might want to add a ornament at the peak of the tree, or perhaps put some decorations within the tree.
[M-22]Write a main() program that
prints a block of stars centered inside a block of dots. Make n, m, N, and M
constants of the program, or make them optional command line parameters. Here
is the output when n==5, m==7, N==11, M==13:
............. ............. ............. ...*******... ...*******... ...*******... ...*******... ...*******... ............. ............. .............
If you need an explanation of command line parameters, look at the answer (or check you C text book.)
[M-12]Write a main() program that
prints an n by n square of characters. Divide the square into quarters, and
fill each quarter with a different character. Here is the output when n==15:
*******........ *******........ *******........ *******........ *******........ *******........ *******........ $$$$$$$oooooooo $$$$$$$oooooooo $$$$$$$oooooooo $$$$$$$oooooooo $$$$$$$oooooooo $$$$$$$oooooooo $$$$$$$oooooooo $$$$$$$oooooooo
For extra fun, make n and the characters for each quadrant command line parameters. (But the answer does not do this.)
[M-8]Write a main() program that prints
an n by n square of characters. Divide the square into 8 horizontal bands. The
bands alternate between star and dot. Declare n as a variable. Here is the output
when n==16:
**************** **************** ................ ................ **************** **************** ................ ................ **************** **************** ................ ................ **************** **************** ................ ................
[M-12]Write a main() program that
prints an n by n square of characters. Make the square out of bands that are
4 characters wide. Use four different characters for the bands, and keep repeating
the bands until the square is finished. Here is the output when n==24:
************************ ************************ ************************ ************************ ........................ ........................ ........................ ........................ oooooooooooooooooooooooo oooooooooooooooooooooooo oooooooooooooooooooooooo oooooooooooooooooooooooo ++++++++++++++++++++++++ ++++++++++++++++++++++++ ++++++++++++++++++++++++ ++++++++++++++++++++++++ ************************ ************************ ************************ ************************ ........................ ........................ ........................ ........................
If n is not a multiple of four, the last band will have fewer than four rows.
[M-8]Write a main() program that prints
an n x n square composed of alternating star and dot characters.
*.*.*.*.*.*.*.*.* .*.*.*.*.*.*.*.*. *.*.*.*.*.*.*.*.* .*.*.*.*.*.*.*.*. *.*.*.*.*.*.*.*.* .*.*.*.*.*.*.*.*. *.*.*.*.*.*.*.*.* .*.*.*.*.*.*.*.*. *.*.*.*.*.*.*.*.* .*.*.*.*.*.*.*.*. *.*.*.*.*.*.*.*.* .*.*.*.*.*.*.*.*. *.*.*.*.*.*.*.*.* .*.*.*.*.*.*.*.*. *.*.*.*.*.*.*.*.* .*.*.*.*.*.*.*.*. *.*.*.*.*.*.*.*.*
Write the program so that it works regardless of whether n is even or odd.
[M-10]Write a main() program that
prints an n by n checkerboard made up of m by m squares. Here is a 24x24 checkboard
made of 6x6 squares:
******......******...... ******......******...... ******......******...... ******......******...... ******......******...... ******......******...... ......******......****** ......******......****** ......******......****** ......******......****** ......******......****** ......******......****** ******......******...... ******......******...... ******......******...... ******......******...... ******......******...... ******......******...... ......******......****** ......******......****** ......******......****** ......******......****** ......******......****** ......******......******
You can use this program to create image files that can be viewed with image processing programs. To do this, do not output "\n" at the end of each line (don't output anything at the end of a line). Change the two characters into '!' and '~'. These characters are at the beginning and at the end of the printable ascii characters. This increases the contrast between the dark and light squares. Now redirect the output of the program to a file:
C:\> check.exe > checkerboard.raw
If you have Adobe Photoshop you can open this file using the "raw" image format. In this image format, each byte of the file corresponds directly to a pixel in the image, and the file has no header or other information in it. You may have to tell Photoshop the size of your image.
Here is what Photoshop shows for a 256x256 raw image:
Most image viewers do not, unfortunately, support raw images. You may have an image viewer that supports "portable gray map" images, PGM. If this is the case, create the file as above but put the following as the first two lines:
P2 256 256 255
Each line ends with "\n". The P2 on the first line says that the image is in PGM format, the next line lists the number of columns, the number of rows, and the maximum gray level.
[M-8]Write a main() program that prints
a square with an 8 character wide band down the diagonal.
****............ *****........... ******.......... *******......... ********........ .********....... ..********...... ...********..... ....********.... .....********... ......********.. .......********. ........******** .........******* ..........****** ...........*****
[H-12]Write a main() program that
prints a square that consists of four triangles. The base of each triangle is
a side of the square, as below. When there is an odd number of columns, the
triangles meet at a point:
| n==17 | n==18 |
|---|---|
***************** .***************. ..*************.. ...***********... ....*********.... .....*******..... ......*****...... .......***....... ........*........ .......***....... ......*****...... .....*******..... ....*********.... ...***********... ..*************.. .***************. ***************** |
****************** .****************. ..**************.. ...************... ....**********.... .....********..... ......******...... .......****....... ........**........ ........**........ .......****....... ......******...... .....********..... ....**********.... ...************... ..**************.. .****************. ****************** |
Getting this to work may take some fussing. Hint: think about the diagonal lines.
[H-8]Write a main() program that prints
a few cycles of a cosine wave down the page.
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
Hint: decide on how many cycles of the wave you want. Multiply that number by two*pi to find how many radians the wave goes through. Divide that by the number of rows to determine the number of radians for each row.
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