Joshua Friedman

Hello!

I've solved the dreaded pyramid problem from the itunes Stanford CS106 course, and created myself a pyramid (hint to those having trouble, try manually coding your first two lines in order to figure out what exactly you want your for loops to do. I could have saved myself about a week of mental anguish if I did that!).

Two issues:

1) The pyramid is not quite centered and I'm having trouble figuring out how to do this: is there a set formula to use and memorize from here on out, or do I need to rework my algorithm?

2) How would you fix this code? If I were an actual CS106 student I'd have a prof and some TAs to help me out...but now I don't so I need your experience . Right now, I have each individual layer being laid from left to right, then measuring to go up by one layer, shift the row by 1/2 a brick length, and lay down one less brick per layer until we have one brick. Is there a better way to go about this that I didn't think of?

Thank you very much!

* File: Pyramid.java * Name: xxxxx * Section Leader: xxxxx * ------------------ * This file is the starter file for the Pyramid problem. * It includes definitions of the constants that match the * sample run in the assignment, but you should make sure * that changing these values causes the generated display * to change accordingly. */ import acm.graphics.*; import acm.program.*; import java.awt.*; public class Pyramid extends GraphicsProgram { /** Width of each brick in pixels */ private static final int BRICK_WIDTH = 30; /** Width of each brick in pixels */ private static final int BRICK_HEIGHT = 12; /** Number of bricks in the base of the pyramid */ private static final int BRICKS_IN_BASE = 14; public void run() { layRow(); } int bricksInRow=BRICKS_IN_BASE; int rowInPyramid=BRICKS_IN_BASE; private void layRow(){ for (int i=1; i<=rowInPyramid; i++){ for (int j=0; j<=bricksInRow; j++){ int x = (j*BRICK_WIDTH)+(i*BRICK_WIDTH/2)+(getWidth()/(4)); int y = (getHeight()-(BRICK_HEIGHT*i)); GRect brick = new GRect (x,y,BRICK_WIDTH,BRICK_HEIGHT); add (brick); } bricksInRow--; rowInPyramid++; } } }

K. Tsang,

Thanks a lot for your reply. You're right, I DID make a mistake in the sign, but even if I change the sign the number never increments and just puts a number of whatever I assigned "date" to be in the square.

Hello!

This is my first post. I am an absolute, total beginner in learning CS and am working through the art and science of Java book to teach myself Java, using a version of Stanford's cs106a class that's on itunes. I'm having a trouble with one of the problems.

I'm supposed to create a very basic calendar that includes the date of the month. On this calendar (stretched from Sunday to Saturday), the month would start on Friday. The number of weeks should also change based upon how many days there are in the month. Instead I get rows of squares, each containing a "0" My code is here:

/* * File: Calendar.java * Trying to make a calendar based on Art and Science of Java * */ import acm.graphics.*; import acm.program.*; import java.awt.*; public class Calendar extends GraphicsProgram { //31 day month in this example private static final int DAYS_IN_MONTH = 31; //day of week. 0=Sunday. 1=Monday. So on and so forth private static final int DAY_MONTH_STARTS =5; private static final int DAY_WIDTH=40; private static final int DAY_HEIGHT=30; //the below should be obvious private static final int DAYS_IN_WEEK=7; public void run(){ //in the case of a week starting on a Friday, we get 36/7=5 weeks using integer division int weeksInMonth=(DAYS_IN_MONTH+DAY_MONTH_STARTS)/(DAYS_IN_WEEK); if (DAYS_IN_MONTH%DAYS_IN_WEEK>0){ weeksInMonth++; } for (int i=0; i<weeksInMonth; i++){ for (int j=0; j<DAYS_IN_WEEK; j++){ int x=j*(DAY_WIDTH); int y=i*(DAY_HEIGHT); GRect calendarDay=new GRect (x,y,DAY_WIDTH,DAY_HEIGHT); add (calendarDay); //HERE IS WHERE I DON'T UNDERSTAND WHAT I AM SUPPOSED TO DO int date=0; GLabel dateLabel= new GLabel(date+"", DAY_WIDTH*j+10,DAY_HEIGHT*i+10); for (int k=date; k<=DAYS_IN_MONTH; k++) if (k>=DAYS_IN_MONTH){ add (dateLabel); date++; }

What ends up happening under these conditions looks like the attached picture. Can anyone here please help me figure out what exactly is going on in these loops and why my dates won't show up properly?

As a related question, what exactly ARE I and J? I imagine the machine as drawing these squares left to right, then moving down, and drawing another row. Using the pause method shows me that's what is happening but as a beginner I'm feeling very, very lost. Any help would be appreciated!


*edit attached a picture of my results