学步园

1.

   Write a GraphicsProgram subclass that draws a pyramid consisting of bricks arranged in horizontal rows, so that the number of bricks in each row decreases by one as you move up the pyramid, as shown in the following sample run:

   The pyramid should be centered at the bottom of the window and should use constants for the following parameters:

BRICK_WIDTH            The width of each brick (30 pixels)

BRICK_HEIGHT           The height of each brick (12 pixels)

BRICKS_IN_BASE        The number of bricks in the base (14)

    The numbers in parentheses show the values for this diagram, but you must be ableto change those values in your program.

程序源代码：

/*<br /> * File: Pyramid.java<br /> * Name:<br /> * Section Leader:<br /> * ------------------<br /> * This file is the starter file for the Pyramid problem.<br /> * It includes definitions of the constants that match the<br /> * sample run in the assignment, but you should make sure<br /> * that changing these values causes the generated display<br /> * to change accordingly.<br /> */<br /> import acm.graphics.*;<br /> import acm.program.*;<br /> import java.awt.*;<br /> public class Pyramid extends GraphicsProgram {<br /> /** Width of each brick in pixels */<br /> private static final int BRICK_WIDTH = 30;<br /> /** Width of each brick in pixels */<br /> private static final int BRICK_HEIGHT = 12;<br /> /** Number of bricks in the base of the pyramid */<br /> private static final int BRICKS_IN_BASE = 14;</p> <p> public void run() {<br /> /* You fill this in. */<br /> /*初始坐标*/<br /> int initX = (getWidth() - BRICK_WIDTH * BRICKS_IN_BASE)/2;<br /> int initY = getHeight() - BRICK_HEIGHT;<br /> /*由最底层向上绘制所需图像*/<br /> for(int i=0;i<BRICKS_IN_BASE;i++){<br /> /*y坐标在绘制每层图像时变化值为BRICK_HEIGHT*/<br /> int yPos = initY - i * BRICK_HEIGHT;<br /> /*初始坐标每次的缩进量为BRICK_WIDTH的一半*/<br /> initX += BRICK_WIDTH/2;<br /> for(int j=0;j<BRICKS_IN_BASE-i;j++){<br /> int xPos = initX + j * BRICK_WIDTH;<br /> GRect br = new GRect(xPos,yPos,BRICK_WIDTH,BRICK_HEIGHT);<br /> add(br);<br /> }<br /> }<br /> }<br /> }<br />