学习进度（7）

今天做了实验二的其余两个实验。

2. 模拟图形绘制

　　对于一个图形绘制程序，用下面的层次对各种实体进行抽象。定义一个 Drawable 的特质，其包括一个 draw 方法，默认实现为输出对象的字符串表示。定义一个 Point 类表示点，其混入了 Drawable 特质，并包含一个 shift 方法，用于移动点。所有图形实体的抽象类为Shape，其构造函数包括一个 Point 类型，表示图形的具体位置（具体意义对不同的具体图形不一样）。Shape 类有一个具体方法 moveTo 和一个抽象方法 zoom，其中 moveTo 将图形从当前位置移动到新的位置， 各种具体图形的 moveTo 可能会有不一样的地方。zoom 方法实现对图形的放缩，接受一个浮点型的放缩倍数参数，不同具体图形放缩实现不一样。继承Shape 类的具体图形类型包括直线类 Line 和圆类 Circle。Line 类的第一个参数表示其位置，第二个参数表示另一个端点，Line 放缩的时候，其中点位置不变，长度按倍数放缩（注意，缩放时，其两个端点信息也改变了），另外，Line 的 move 行为影响了另一个端点，需要对move 方法进行重载。Circle 类第一个参数表示其圆心，也是其位置，另一个参数表示其半径，Circle 缩放的时候，位置参数不变，半径按倍数缩放。另外直线类 Line 和圆类 Circle都混入了 Drawable 特质，要求对 draw 进行重载实现，其中类 Line 的 draw 输出的信息样式为“Line:第一个端点的坐标--第二个端点的坐标)”，类 Circle 的 draw 输出的信息样式为“Circle center:圆心坐标,R=半径”。如下的代码已经给出了 Drawable 和 Point 的定义，同时也给出了程序入口 main 函数的实现，请完成 Shape 类、Line 类和 Circle 类的定义。

case class Point(var x:Double,var y:Double) extends Drawable{
def shift(deltaX:Double,deltaY:Double){x+=deltaX;y+=deltaY}
}
trait Drawable{
def draw(){println(this.toString)}
}
// 请完成 Shape 类、Line 类和 Circle 类的定义。
object MyDraw{
def main(args: Array[String]) {
val p=new Point(10,30)
p.draw;
val line1 = new Line(Point(0,0),Point(20,20))
line1.draw
line1.moveTo(Point(5,5)) //移动到一个新的点
line1.draw
line1.zoom(2) //放大两倍
line1.draw
val cir= new Circle(Point(10,10),5)
cir.draw
cir.moveTo(Point(30,20))
cir.draw
cir.zoom(0.5)
cir.draw
}
}

编译运行程序，期望的输出结果如下：

Point(10.0,30.0)

Line:(0.0,0.0)--(20.0,20.0)

Line:(5.0,5.0)--(25.0,25.0)

Line:(-5.0,-5.0)--(35.0,35.0)

Circle center:(10.0,10.0),R=5.0

Circle center:(30.0,20.0),R=5.0

Circle center:(30.0,20.0),R=2.5

case class Point(var x:Double ,var y:Double) extends Drawable{
    def shift(X:Double ,Y:Double){
        x += X
        y += Y
    }
}
trait Drawable{
    def draw(){println(this.toString)}
}
abstract class Shape(var location:Point)
{
    def moveTo(newLocation:Point)
    {
        location = newLocation
    }
    def zoom(scale:Double)
}
class Line(beginPoint:Point,var endPoint:Point)extends Shape(beginPoint) with Drawable{
    override def draw()
    {
        println(s"Line:(${location.x},${location.y}--(${endPoint.x},${endPoint.y})")
    }
    override def moveTo(newLocation:Point)
    {
        endPoint.shift(newLocation.x-location.x,newLocation.y-location.y)
        location = newLocation
    }
     override def zoom(scale:Double)
     {
        val midPoint=Point((endPoint.x+location.x)/2,(endPoint.y+location.y)/2)
        location.x=midPoint.x+scale*(location.x-midPoint.x)
        location.y=midPoint.y+scale*(location.y-midPoint.y)
        endPoint.x=midPoint.x+scale*(endPoint.x-midPoint.x)
        endPoint.y=midPoint.y+scale*(endPoint.y-midPoint.y)
     }
  
}
class Circle(center:Point,var radius:Double)extends Shape(center) with Drawable
{
    override def draw()
    {
        println(s"Circle center:(${location.x},${location.y}),R=$radius")
    }
    override def zoom(scale :Double)
    {
        radius = radius*scale
    }
}
object MyDraw
{
    def main(args:Array[String])
    {
        val p = new Point(10,30)
        p.draw
        val line1 = new Line(Point(0,0),Point(20,20))
        line1.draw
        line1.moveTo(Point(5,5))
        line1.draw
        line1.zoom(2)
        line1.draw
        val circle = new Circle(Point(10,10),5)
        circle.draw
        circle.moveTo(Point(30,20))
        circle.draw
        circle.zoom(0.5)
        circle.draw
    }
}

3. 统计学生成绩

学生的成绩清单格式如下所示，第一行为表头，各字段意思分别为学号、性别、课程名

1、课程名 2 等，后面每一行代表一个学生的信息，各字段之间用空白符隔开

Id gender Math English Physics

301610 male 80 64 78

301611 female 65 87 58

...

给定任何一个如上格式的清单（不同清单里课程数量可能不一样），要求尽可能采用函数式编程，统计出各门课程的平均成绩，最低成绩，和最高成绩；另外还需按男女同学分开，分别统计各门课程的平均成绩，最低成绩，和最高成绩。

测试样例 1 如下：

Id gender Math English Physics

301610 male 80 64 78

301611 female 65 87 58

301612 female 44 71 77

301613 female 66 71 91

301614 female 70 71 100

301615 male 72 77 72

301616 female 73 81 75

301617 female 69 77 75

301618 male 73 61 65

301619 male 74 69 68

301620 male 76 62 76

301621 male 73 69 91

301622 male 55 69 61

301623 male 50 58 75

301624 female 63 83 93

301625 male 72 54 100

301626 male 76 66 73

301627 male 82 87 79

301628 female 62 80 54

301629 male 89 77 72

样例 1 的统计结果输出为：

course average min max

Math: 69.20 44.00 89.00

English: 71.70 54.00 87.00

Physics: 76.65 54.00 100.00

course average min max (males)

Math: 72.67 50.00 89.00

English: 67.75 54.00 87.00

Physics: 75.83 61.00 100.00

course average min max (females)

Math: 64.00 44.00 73.00

English: 77.63 71.00 87.00

Physics: 77.88 54.00 100.00

测试样例 2

Id gender Math English Physics Science

301610 male 72 39 74 93

301611 male 75 85 93 26

301612 female 85 79 91 57

301613 female 63 89 61 62

301614 male 72 63 58 64

301615 male 99 82 70 31

301616 female 100 81 63 72

301617 male 74 100 81 59

301618 female 68 72 63 100

301619 male 63 39 59 87

301620 female 84 88 48 48

301621 male 71 88 92 46

301622 male 82 49 66 78

301623 male 63 80 83 88

301624 female 86 80 56 69

301625 male 76 69 86 49

301626 male 91 59 93 51

301627 female 92 76 79 100

301628 male 79 89 78 57

301629 male 85 74 78 80

样例 2 的统计结果为：

course average min max

Math: 79.00 63.00 100.00

English: 74.05 39.00 100.00

Physics: 73.60 48.00 93.00

Science: 65.85 26.00 100.00

course average min max

Math: 77.08 63.00 99.00

English: 70.46 39.00 100.00

Physics: 77.77 58.00 93.00

Science: 62.23 26.00 93.00

course average min max

Math: 82.57 63.00 100.00

English: 80.71 72.00 89.00

Physics: 65.86 48.00 91.00

Science: 72.57 48.00 100.00

import scala.collection.mutable.ArrayBuffer
   
object test {
  def main(args: Array[String]): Unit = {
    var students:ArrayBuffer[Student] = new ArrayBuffer[Student]()
    students.append(new Student(301610, "male", 80, 64, 78))
    students.append(new Student(301611, "female", 65, 87, 58))
    students.append(new Student(301612, "female", 44, 71, 77))
    students.append(new Student(301613, "female", 66, 71, 91))
    students.append(new Student(301614, "female", 70, 71, 100))
    students.append(new Student(301615, "male", 72, 77, 72))
    students.append(new Student(301616, "female", 73, 81, 75))
    students.append(new Student(301617, "female", 69, 77, 75))
    students.append(new Student(301618, "male", 73, 61, 65))
    students.append(new Student(301619, "male", 74, 69, 68))
    students.append(new Student(301620, "male", 76, 62, 76))
    students.append(new Student(301621, "male", 73, 69, 91))
    students.append(new Student(301622, "male", 55, 69, 61))
    students.append(new Student(301623, "male", 50, 58, 75))
    students.append(new Student(301624, "female", 63, 83, 93))
    students.append(new Student(301625, "male", 72, 54, 100))
    students.append(new Student(301626, "male", 76, 66, 73))
    students.append(new Student(301627, "male", 82, 87, 79))
    students.append(new Student(301628, "female", 62, 80, 54))
    students.append(new Student(301629, "male", 89, 77, 72))
    println(students.length)
    println(students(1).toString)
   
    getData(students)
    getDataMale(students)
    getDataFeMale(students)
  }
  def getData(value: ArrayBuffer[Student]): Unit ={
    var Mathaverage:Double=0;
    var MathSum:Double = 0;
    var MathMin:Double = value(0).Math;
    var MathMax:Double = 0;
   
    var Englishaverage:Double=0;
    var EnglishSum:Double = 0;
    var EnglishMin:Double = value(0).English;
    var EnglishMax:Double = 0;
   
    var Physicsaverage:Double=0;
    var PhysicsSum:Double = 0;
    var PhysicsMin:Double = value(0).Physics;
    var PhysicsMax:Double = 0;
   
    var number = value.length;
    for (i <- 0 until value.length){
      //三科总数
      MathSum = value(i).Math+MathSum
      EnglishSum = value(i).English+EnglishSum
      PhysicsSum = value(i).Physics+PhysicsSum
      //最大和最小
      if(value(i).Math>MathMax){
        MathMax=value(i).Math;
      }
      if(value(i).English>EnglishMax){
        EnglishMax=value(i).English;
      }
      if(value(i).Physics>PhysicsMax){
        PhysicsMax=value(i).Physics;
      }
      if(value(i).Math<MathMin){
        MathMin=value(i).Math;
      }
      if(value(i).English<EnglishMin){
        EnglishMin=value(i).English;
      }
      if(value(i).Physics<PhysicsMin){
        PhysicsMin=value(i).Physics;
      }
    }
    //平均值
    Mathaverage=MathSum/number
    Englishaverage=EnglishSum/number
    Physicsaverage=PhysicsSum/number
    println("course	 average	 min	 max 	")
    println("Math:	   "+Mathaverage+"		"+MathMin+"	 "+MathMax)
    println("English:	"+Englishaverage+"	"+EnglishMin+"	 "+EnglishMax)
    println("Physics:	"+Physicsaverage+"	"+PhysicsMin+"	 "+PhysicsMax)
  }
   
  def getDataMale(value: ArrayBuffer[Student]): Unit = {
    var Mathaverage: Double = 0;
    var MathSum: Double = 0;
    var MathMin: Double = value(0).Math;
    var MathMax: Double = 0;
   
    var Englishaverage: Double = 0;
    var EnglishSum: Double = 0;
    var EnglishMin: Double = value(0).English;
    var EnglishMax: Double = 0;
   
    var Physicsaverage: Double = 0;
    var PhysicsSum: Double = 0;
    var PhysicsMin: Double = value(0).Physics;
    var PhysicsMax: Double = 0;
   
    var number = 0;
   
    for (i <- 0 until value.length) {
      if (value(i).gender.equals("male")) {
        number = number + 1
        //三科总数
        MathSum = value(i).Math + MathSum
        EnglishSum = value(i).English + EnglishSum
        PhysicsSum = value(i).Physics + PhysicsSum
        //最大和最小
        if (value(i).Math > MathMax) {
          MathMax = value(i).Math;
        }
        if (value(i).English > EnglishMax) {
          EnglishMax = value(i).English;
        }
        if (value(i).Physics > PhysicsMax) {
          PhysicsMax = value(i).Physics;
        }
        if (value(i).Math < MathMin) {
          MathMin = value(i).Math;
        }
        if (value(i).English < EnglishMin) {
          EnglishMin = value(i).English;
        }
        if (value(i).Physics < PhysicsMin) {
          PhysicsMin = value(i).Physics;
        }
      }
   
    }
    //平均值
    Mathaverage=MathSum/number
    Englishaverage=EnglishSum/number
    Physicsaverage=PhysicsSum/number
    println("course	 average	 min	 max 	(Male)")
    Mathaverage=Mathaverage.toInt
    Englishaverage=Englishaverage.toInt
    Physicsaverage=Physicsaverage.toInt
    println("Math:	   "+Mathaverage+"		"+MathMin+"	 "+MathMax)
    println("English:	   "+Englishaverage+"		"+EnglishMin+"	 "+EnglishMax)
    println("Physics:	   "+Physicsaverage+"		"+PhysicsMin+"	 "+PhysicsMax)
  }
   
  def getDataFeMale(value: ArrayBuffer[Student]): Unit ={
    var Mathaverage:Double=0;
    var MathSum:Double = 0;
    var MathMin:Double = value(1).Math;
    var MathMax:Double = 0;
   
    var Englishaverage:Double=0;
    var EnglishSum:Double = 0;
    var EnglishMin:Double = value(1).English;
    var EnglishMax:Double = 0;
   
    var Physicsaverage:Double=0;
    var PhysicsSum:Double = 0;
    var PhysicsMin:Double = value(1).Physics;
    var PhysicsMax:Double = 0;
   
    var number = 0;
   
    for (i <- 0 until value.length){
      if(value(i).gender.equals("female")){
        number=number+1
        //三科总数
        MathSum = value(i).Math+MathSum
        EnglishSum = value(i).English+EnglishSum
        PhysicsSum = value(i).Physics+PhysicsSum
        //最大和最小
        if(value(i).Math>MathMax){
          MathMax=value(i).Math;
        }
        if(value(i).English>EnglishMax){
          EnglishMax=value(i).English;
        }
        if(value(i).Physics>PhysicsMax){
          PhysicsMax=value(i).Physics;
        }
        if(value(i).Math<MathMin){
          MathMin=value(i).Math;
        }
        if(value(i).English<EnglishMin){
          EnglishMin=value(i).English;
        }
        if(value(i).Physics<PhysicsMin){
          PhysicsMin=value(i).Physics;
        }
      }
    }
    //平均值
    Mathaverage=MathSum/number
    Englishaverage=EnglishSum/number
    Physicsaverage=PhysicsSum/number
    println("course	 average	 min	 max 	(FeMale)")
    Mathaverage=Mathaverage.toInt
    Englishaverage=Englishaverage.toInt
    Physicsaverage=Physicsaverage.toInt
    println("Math:	   "+Mathaverage+"		"+MathMin+"	 "+MathMax)
    println("English:	   "+Englishaverage+"		"+EnglishMin+"	 "+EnglishMax)
    println("Physics:	   "+Physicsaverage+"		"+PhysicsMin+"	 "+PhysicsMax)
  }
}
class Student(id1:Int,gender1:String,Math1:Double,English1:Double,Physics1:Double){
  var id:Int = id1
  var gender:String = gender1
  var Math:Double = Math1
  var English:Double = English1
  var Physics:Double = Physics1
   
  override def toString = s"Student($id, $gender, $Math, $English, $Physics)"
}