p6hsylpbf/Mainn.java

package test;
import java.util.Arrays;
import java.util.Scanner;
import java.util.*;
class power{

public static int factorial(int n){
		int factorial=1;
		int counter=1;
		while (counter<1+n){
			factorial*=counter+1;
			counter++;
		}
		return factorial;
	}	
public static double ex(int n,int x){
	double ex=1.0;
	int counter=1;
	while (counter<=n){
		ex+=(double)Math.pow(x,counter)/factorial(counter);
		counter++;
	}
	return ex;
}	



}

class b {
    public static void main(String[] args) {
    	int a;
    	int x;
    	double result;
    	System.out.println("输入底数a(a>0且a！=1):");
    	Scanner sc = new Scanner(System.in);
    	a=sc.nextInt();		
    	System.out.println("输入真数x:");
    	x=sc.nextInt();		
        result = log(x, a);
        System.out.println(result);
    }
 
    public static double log(double value, double base) {
        return Math.log10(value) / Math.log10(base);
    }
}
class CALC{
	public static void main(String args[]){
		double x;
		double y;
		String z;
		Scanner sc=new Scanner(System.in);
		System.out.println("输入第一个数：");
		x=sc.nextDouble();
		System.out.println("输入运算符：");
		z=sc.next();
		System.out.println("输入第二个数：");
		y=sc.nextDouble();
		System.out.print("结果是：");
		switch(z){
		case"+":System.out.println(x+y);
			break;
		case"-":System.out.println(x-y);
			break;
		case"*":System.out.println(x*y);
			break;
		case"/":System.out.println(x/y);
			break;
		}
	}
}

class d {
	String s;
	double x;
	public d(String s,double x)
	{
		this.s=s;
		this.x=x;
	}
	public  double sanjiao()
	{
		if (s.equals("sin")) return sin(x);
		else if (s.equals("cos")) return cos(x);
		else if (s.equals("tan")) return tan(x);
		else if (s.equals("asin")) return asin(x);
		else if (s.equals("acos")) return acos(x);
		else if (s.equals("atan")) return atan(x);
		else return Double.POSITIVE_INFINITY;
	}
	private double sin(double x) {return Math.sin(x);}
	private double cos(double x) {return Math.cos(x);}
	private double tan(double x) {return Math.tan(x);}
	private double asin(double x) {return Math.asin(x);}
	private double acos(double x) {return Math.acos(x);}
	private double atan(double x) {return Math.atan(x);}
}
public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner s=new Scanner(System.in);
		System.out.println("1 for e^x\n2 for logax\n3 for +-*/\n4 for 三角函数");
		int calnum=s.nextInt();//选择数字决定进行哪种运算
		if(calnum ==1){
			System.out.println("type x:");
			Scanner x=new Scanner(System.in);
			System.out.println("result:"+power.ex(1, x.nextInt()));
		}
		if(calnum==2) {
			int a,x;
			System.out.println("type a:");
			Scanner sc=new Scanner(System.in);
			a=sc.nextInt();
			System.out.println("type x:");
			x=sc.nextInt();
			System.out.println("result:"+b.log(x,a));
		}
		if(calnum==3) {
			double x;
			double y;
			String z;
			Scanner sc=new Scanner(System.in);
			System.out.println("type the first number：");
			x=sc.nextDouble();
			System.out.println("type calculation symbol：");
			z=sc.next();
			System.out.println("type the second number：");
			y=sc.nextDouble();
			System.out.print("result：");
			switch(z){
			case"+":System.out.println(x+y);
				break;
			case"-":System.out.println(x-y);
				break;
			case"*":System.out.println(x*y);
				break;
			case"/":System.out.println(x/y);
				break;
		}
	}
		if(calnum==4) {
			System.out.println("choose sin,cos,tan,asin,acos or atan");
			String ss;double x;
			Scanner sc=new Scanner(System.in);
			ss=sc.nextLine();
			System.out.print("type x:");
			x=sc.nextDouble();
			d ch=new d(ss,x);
			System.out.print("result："+ch.sanjiao());
		}
		}

}