printint.java

一些Java的小的应用程序

/**一个健壮的数字打印程序；
 * 一个可以打出任何进制的程序。
 * */import java.io.BufferedReader;
import java.io.InputStreamReader;
public final class PrintInt {
private static final String DIGIT_TABLE="0123456789abcdefg";
//a=10 b=11 c=12 d=13 e=14 f=15 g=16 h=17 i=18 j=19 k=20 l=21 
//m=22 n=23 o=24 p=25 q=26 r=27 s=28 t=29 u=30 v=31 w=32 x=33
//y=34 z=35 
//A=36 B=37 C=38 D=39 E=40 F=41 G=42 H=43 I=44 J=45 K=46 L=47
//M=48 N=49 O=50 P=51 Q=52 R=53 S=54 T=55 U=56 V=57 W=58 X=59 
//Y=60 Z=61
private static final int MAX_BASE =DIGIT_TABLE.length();
//Print n in any base,recursively
//Precondition :n>=0,2<=base<=MAX_BASE
private static void printIntRec (long n,int base){
	if(n>=base)printIntRec(n/base,base);
	System.out.print(DIGIT_TABLE.charAt((int)(n%base)));
}//Driver routine
public static void printInt(long n,int base){
	if(base<=1|base>MAX_BASE)
		System.out.println("Can'nt print in base "+base);
	else{
		if(n<0){
			n=-n;
			System.out.print("-");
		}printIntRec(n,base);
	}
}public static void main(String args[]){
	try{BufferedReader input=new BufferedReader
		(new InputStreamReader(System.in));
	String ans="n";
	while(!(ans.equalsIgnoreCase("y"))){
	System.out.println("Enter the base:");
	int base=Integer.parseInt(input.readLine());
	System.out.println("Enter the number:");
	long n=Long.parseLong(input.readLine());
	System.out.println("The result is :");
	printInt(n,base);
	
	System.out.println("\nContinue(any key except y) or stop(y)");
	ans=input.readLine();
	}
}
	catch(Exception e){
		System.out.println("ERROR!");
	}}}