10.24（周二）

1.public class Date

{

 

     int year;

 

 int month;

 

 int day;

 

public void setDate(int y, int m, int d){

 

year=y;

 

month=m;

 

day=d;

 

}

public int getYear(){

 

    return year;

 

}

public int getMonth(){

    return month;

 

}

public int getDay(){

 

    return day;

 

}

public boolean isLeapYear()

 

{

boolean isLeap=true;

 

if(this.year%100==0)

 

{

if(this.year%400==0)

 

isLeap=true;

else isLeap=false;

 

return isLeap;

}

else

{

if(this.year%4==0&&this.year%100!=0)

 

isLeap=true;

else isLeap=false;

 

return isLeap;

 

}

 

}

public void display(){

System.out.println("当前日期是"+this.getYear()+"年"+this.getMonth()+"月"+this.getDay()+"日");

}

 

}

 

public class zuoye2_1{

 

public static void main(String [] args){

 

Date date = new Date();

date.setDate(1900, 1, 1);

 

boolean isLeap=date.isLeapYear();

if(isLeap)

 

System.out.println(date.getYear()+"是闰年");

 

else

 

System.out.println(date.getYear()+"不是闰年");

 

date.display();

 

}

 

}

2.public class Triangle {

 

    private double x, y, a;

 

    public Triangle(int xx, int yy, int aa)

        x = xx;

        y = yy;

        a = aa;

    }

 

    public double area() {

   

        return x * y * Math.sin(a) / 2;

    }

 

    public void changeAng(double aa) {

        a = aa;

    }

 

    public String toString() {

        return "两边长 " + x + " 和 " + y +

        " ,夹角为 " + a + " 的面积为 " + area();

    }

 

    static public void main(String args[]) {

       

        Triangle a = new Triangle(3, 4, Math.PI / 3);

        

        Triangle b = new Triangle(1, 1, Math.PI / 4);

       

        System.out.println(a);

        System.out.println(b);

        b.changeAng(Math.PI / 2);

        System.out.println(b);

    }

}

public class zuoye2_3 {

 private double a;

 private double b;

 private double c;

 private double[] d;

 public String[] i;

 public void setValue( int aa, int bb, int cc) {

  a = aa;

  b = bb;

  c = cc;

  this.d = new double[2];

  this.i = new String[2];

 }

 public boolean canGetValue() {

  double temp;

  temp = b * b - 4 * a * c;

  if (temp < 0) {

   this.i[0] = (-b) / (a * 2) + "+" + Math.sqrt(-temp) / (2 * a) + "i";

   this.i[1] = (-b) / (a * 2) + "-" + Math.sqrt(-temp) / (2 * a) + "i";

   return false;

  } else {

   this.d[0] = (-b + Math.sqrt(temp)) / (2 * a);

   this.d[1] = (-b - Math.sqrt(temp)) / (2 * a);

   return true;

  }

 }

 

 public double getA() {

  return a;

 }

 public double getB() {

  return b;

 }

 public double getC() {

  return c;

 }

 public double getD(int i) {

  return d[i];

 }

 public static void main(String[] args) {

  

  zuoye2_3 shizi = new zuoye2_3();

  shizi.setValue(1, 3, 4);

  if (shizi.canGetValue()) {

   System.out.println(shizi.getA());

   System.out.println(shizi.getB());

   System.out.println(shizi.getC());

   System.out.println(shizi.getD(0));

   System.out.println(shizi.getD(1));

  } else {

   System.out.println(shizi.i[0]);

   System.out.println(shizi.i[1]);

  }

 }

}

 

Complex 类

public class Complex {

int x,y;//定义两个属性 实部和虚部

Complex(){//默认构造函数

x=0;

y=0;

}

int getx(){

return x;

}

int gety(){

return y;

}

void showcomp(){//显示复数的方法

if(x==0){

System.out.println(y+"i");

}

else if(y>0)

System.out.println(x+"+"+y+"i");

else if(x==0&&y==0){

System.out.println("0");

}

else

System.out.println(x+""+y+"i");

}

Complex(int i,int j){

x=i;

y=j;

}

static Complex addcomp(Complex c1,Complex c2){

Complex b= new Complex(c1.getx()+c2.getx(),c2.gety()+c1.gety());

return b;

}

static Complex subcomp(Complex c1,Complex c2){

Complex b = new Complex(c1.getx()-c2.getx(),c1.gety()-c2.gety());

return b;

}

static Complex mulitcomp(Complex c1,Complex c2){

Complex b = new Complex(c1.getx()*c2.getx()-c1.gety()*c2.gety(),c1.getx()*c2.gety()+c2.getx()*c1.gety());

return b;

}

public static boolean equalComp(Complex c1,Complex c2){

boolean b;

if(c1.x==c2.x&&c1.y==c2.y)

b=true;

else

b=false;

return b;

}

}

 

 

import java.util.*;

public class zuoye2_4{

public static void main(String args[]){

Scanner reader = new Scanner(System.in);

int x=reader.nextInt();

int y=reader.nextInt();

int x2=reader.nextInt();

int y2=reader.nextInt();

Complex c1,c2,c3;

boolean c4;

c1 = new Complex(x,y);

c2 = new Complex(x2,y2);

c3 = new Complex();

System.out.println("计算二个复数的加法");

c3=Complex.addcomp(c1, c2);

c3.showcomp();

System.out.println("计算二个复数的减法");

c3=Complex.subcomp(c1, c2);

c3.showcomp();

System.out.println("计算二个复数的乘法");

c3=Complex.mulitcomp(c1, c2);

c3.showcomp();

System.out.println("判断二个复数是否相等");

c4=Complex.equalComp(c1, c2);

if(c4){

System.out.println("二个复数是相等");

}

else

System.out.println("二个复数不相等");

}

}