package cal;
import java.util.Scanner;
import java.math.*;

public class Calculator {
    public static void main(String[] args) 
    {
        Scanner sc=new Scanner(System.in);
        double result=1.0;
        System.out.println("对数 0;sin 6;cos 7;tan 8;e的指数 1；加 2；减 3；乘 4；除 5 ");
        String Command=sc.nextLine();
        System.out.println("输入对应运算数值 两数以空格间隔");
        String parameters=sc.nextLine();
        if(Command.equals("0"))
            result=Calculator.Log(parameters);
          else if(Command.equals("1"))
          {
              //double x=Double.parseDouble(parameters);
              ExFunction e = new ExFunction(Double.parseDouble(parameters));
              result=e.index();
          }
          else if(Command.equals("2"))
            {
              String[] s=new String[2];
             s=parameters.split(" ");
             double a=Double.parseDouble(s[0]);
             double b=Double.parseDouble(s[1]);
              jjcc e = new jjcc();
              result = e.add(a,b);
          }
          else if(Command.equals("3"))
             {
              String[] s=new String[2];
             s=parameters.split(" ");
             double a=Double.parseDouble(s[0]);
             double b=Double.parseDouble(s[1]);
              jjcc e = new jjcc();
              result = e.sub(a,b);
          } 
          else if(Command.equals("4"))
                  {
              String[] s=new String[2];
             s=parameters.split(" ");
             double a=Double.parseDouble(s[0]);
             double b=Double.parseDouble(s[1]);
              jjcc e = new jjcc();
              result = e.mul(a,b);
          }
          else if(Command.equals("5"))
          {
              String[] s=new String[2];
             s=parameters.split(" ");
             double a=Double.parseDouble(s[0]);
             double b=Double.parseDouble(s[1]);
              jjcc e = new jjcc();
              result = e.div(a,b);
          }
        
          else if(Command.equals("6"))
        	  result=Calculator.sin(parameters);
          else if(Command.equals("7"))
        	  result=Calculator.cos(parameters);
          else if(Command.equals("8"))
        	  result=Calculator.tan(parameters);
        System.out.println(result);
        
    }
    public static double Log(String s)
    {
        String[] parameters=new String[2];
        parameters=s.split(" ");
        float a=Float.parseFloat(parameters[0]);
        float b=Float.parseFloat(parameters[1]);
        double result=Math.log(b)/Math.log(a);  
        return result;
    }
    public static double sin(String s)
    {
       double x=Double.parseDouble(s);
       return Math.sin(Math.toRadians(x));//Math.toRadians()将角度转换为弧度	   
    }
    public static double cos(String s)
    {
    	double x=Double.parseDouble(s); 
        return Math.cos(Math.toRadians(x));
    }
    public static double tan(String s)
    {
    	double x=Double.parseDouble(s); 
    	return Math.tan(Math.toRadians(x));
    }
    
//    public static double jjcc()
//    {
//        
//    }
//    public static double ex()
//    {
//        
//    }
}
    class ExFunction {
        public double x;

        public ExFunction(double x) {
            this.x = x;
        }

        public double index() {
            return Math.exp(x);
        }

}
 class jjcc {
    
    public double x;

        public jjcc() {
            
        }
    public  double add(double a,double b)
    {
        return a+b;
    }
    public static double sub(double a,double b)
    {
        return a-b;
    }
    public static double mul(double a,double b)
    {
        return a*b;
    }
    public static double div(double a,double b)
    {
        return (double)a/b;
    }
}