stanford编程方法学karel作业一problem2

/*
 * File: StoneMasonKarel.java
 * --------------------------
 * The StoneMasonKarel subclass as it appears here does nothing.
 * When you finish writing it, it should solve the "repair the   quad"
 * problem from Assignment 1.  In addition to editing the   program,
 * you should be sure to edit this comment so that it no longer
 * indicates that the program does nothing.
 */

import stanford.karel.*;

public class StoneMasonKarel extends SuperKarel {
  public void run(){
      while(frontIsClear()){
          turnEast();               //将起始位置朝东
          SetColumnStone();     //将一列全部填满
          turnBack();               //填满一列后回到该列下方
          move4times();         //移动四列
        }
    
        //为了让最后一列也可以判断，需要加上最后一次循环
        SetColumnStone();       //将一列全部填满
        turnBack();             //填满一列后回到该列    下方
        }
    private void move4times() {
      turnLeft();
      for(int i=0;i<4;i++){
          move();
      }
    }

  //转向东
  private void turnEast() {
      while(notFacingEast()){       //如果不是朝东，向左转，直到朝东
          turnLeft();
      }
  }

  //返回下方
  private void turnBack() {
      turnAround();
      while(frontIsClear()){
          move();
      }
  }

  //填满一列
  private void SetColumnStone() {
      turnLeft();                   //出发时向左拐
      while(frontIsClear()){
          if(noBeepersPresent()){       //判断当前位置是否有beeper
              putBeeper();
          }
          move();
      }
      if(noBeepersPresent()){       //判断当前位置是否有beeper,防止最后一个判断错误
          putBeeper();
      }
  }
}