ex030202.java

我在学习JAVA的讲义

import java.io.*;
public class Ex030202{
	static long method1(int x){
		int fx=0;
				
		if (x<0)
			fx=2*x-1;
		else if (x<3 && x>=0)
			fx=3*x+5;
		else if (x<5 && x>=3)
			fx=x+1;
		else if (x<10 && x>=5)
			fx=5*x-3;
		else if (x>=10)
			fx=7*x+2;
		return fx;
	}

	static long method2(int x){
		int fx=0;
				
		switch(x) {
		case 0:
		case 1:
		case 2:
			fx=3*x+5;
			break;
		case 3:
		case 4:
			fx=x+1;
			break;
		case 5:
		case 6:
		case 7:
		case 8:
		case 9:
			fx=5*x-3;
			break;
		default:
			if (x>=10)
				fx=7*x+2;
			else
				fx=2*x-1;
		}
		return fx;
	}

	public static void main(String[] args){
		int x=0;
		Reader ir = new InputStreamReader(System.in);
		BufferedReader r = new BufferedReader(ir);
		String sc="";
		System.out.print(" x = ");
		try{
			sc = r.readLine();
		}catch (IOException e){}
		try{
			x=Integer.parseInt(sc);
		}catch (NumberFormatException e){
			System.out.println("输入的数据不是整数");
			System.exit(1);
		}
		System.out.println("f(x) = "+method1(x));
		System.out.println("f(x) = "+method2(x));
	}
}