习题或作业 01

1. 根据现有的函数画 5 环.

import acm.graphics.*;
import acm.program.*;
import java.awt.*;

public class OlympicRings extends GraphicsProgram {
    
    public void run() {
        draw3Circle(100, 100, circleR, Color.green);
        draw3Circle(100+distance, 100, circleR, Color.red);
        draw3Circle(100+distance+distance, 100, circleR, Color.blue);
        draw3Circle(newOrigalW, newOrigalH, circleR, Color.yellow);
        draw3Circle(newOrigalW+distance, newOrigalH, circleR, Color.black);
    }
    
    private int circleR = 100;
    private int circleSpace = 20;
    private int distance = circleR + circleSpace;
    private int newOrigalW = 100 + circleR/2 + circleSpace/2;
    private int newOrigalH = 100 + circleR/2 + circleSpace/2;
    
    private void draw3Circle(int originalW, int originalH, int radius, Color temp) {
        for (int i=0; i<5; i++) {
            GOval oo = new GOval(originalW+i, originalH+i, radius-(i*2), radius-(i*2));
            oo.setColor(temp);
            add(oo);
        }
    }
}

运行结果:

2. Rainbow

思路, 画大圆, 多层的, 西边部分用一个大的rect(白色的) 覆盖掉.

import acm.graphics.*;
import acm.program.*;
import java.awt.*;

public class Rainbow extends GraphicsProgram {
    public void run() {
        drawCircles(originalW, originalH, circleR, Color.black);
        drawCircles(originalW+regularDistance*1, originalH+regularDistance*1, circleR-regularDistance*1*2, Color.yellow);
        drawCircles(originalW+regularDistance*2, originalH+regularDistance*2, circleR-regularDistance*2*2, Color.blue);
        drawCircles(originalW+regularDistance*3, originalH+regularDistance*3, circleR-regularDistance*3*2, Color.red);
        drawCircles(originalW+regularDistance*4, originalH+regularDistance*4, circleR-regularDistance*4*2, Color.orange);
        drawCircles(originalW+regularDistance*5, originalH+regularDistance*5, circleR-regularDistance*5*2, Color.green);
        drawCircles(originalW+regularDistance*6, originalH+regularDistance*6, circleR-regularDistance*6*2, Color.GRAY);
        
        GRect rc = new GRect(100, 200, rectW, rectH);
        rc.setFilled(true);
        rc.setColor(Color.white);
        rc.setFillColor(Color.white);
        add(rc);
    }
    
    private void drawCircles(int originalW, int originalH, int radius, Color temp) {
        for (int i=0; i<5; i++) {
            GOval oo = new GOval(originalW+i, originalH+i, radius-(i*2), radius-(i*2));
            oo.setColor(temp);
            add(oo);
        }
    }
    
    private int originalW = 100;
    private int originalH = 100;
    private int circleR = 1000;
    private int rectW = 2000;
    private int rectH = 2000;
    private int regularDistance = 5;
}

运行结果:

 3. 金字塔

/*
 * File: Pyramid.java
 * Name: 
 * Section Leader: 
 * ------------------
 * 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;
    
    private int startX = 50;
    private int startY = 300;
    
    public void run() {
        /* You fill this in. */
        
        for (int i=0; i<BRICKS_IN_BASE; i++) {
            int rowX = startX + i*(BRICK_WIDTH/2);
            int currentY = startY - i*BRICK_HEIGHT;
            for (int j=0; j<BRICKS_IN_BASE-i; j++) {
                int currentX = rowX + (BRICK_WIDTH*j);
                GRect gr = new GRect(currentX, currentY, BRICK_WIDTH, BRICK_HEIGHT);
                add(gr);
            }
        }
        
    }
}

运行结果:

 4. 右手规则迷宫

import stanford.karel.*;

public class Maze extends SuperKarel{
    
    public void run() {
        while (!beepersPresent()) {
            if(!rightBlock()) {
                turnRight();
                move();
            } else if (!frontIsBlocked()) {
                move();
            } else {
                turnAround();
            }
        }
    }

    private boolean rightBlock() {
        turnRight();
        boolean right = false;
        if (frontIsBlocked()) {
            right = true;
        } else {
            right = false;
        }
        turnLeft();
        return right;
    }     
}

原则: 按照优先原则

1. 右手边有路, 就转右, 然后前进.

2. 如果右手边是墙, 前方能走, 就前进下一格.

3. 如果无法前进, 右手边也不能转, 就转向.(换一个右手墙, 因为之前的右手墙是死胡同)