产生一个随机四位数

今天去看了下中软实习笔试题,最后一道是编程题.

 

问题描述: 产生一个随机四位数,其中各位数值不相同.

 

程序实现:

 

 

/**
 * Copyright (c) 2011 Trusted Software and Mobile Computing(TSMC)
 * All rights reserved.
 * Author: Jarg Yee <[email protected]>
 * http://jarg.iteye.com/
 */
import java.util.*;
/*
 * 
 */
public class Four
{
	public static void main(String[] args)
	{
		int result = createNumber();
		System.out.println("result:" + result);
	}

	public static int createNumber()
	{
		int count =0;
		int result = 0;
		List<Integer> list = new ArrayList<Integer>();
		while(true)
		{
			result = (int)(Math.random()*10);
			if(count==0)
			{
				if(result!=0)
				{
					list.add(result);
					count++;
				}
			}
			else
			{
				if(count==4)
					break;
				if(list.contains(result))
					continue;
				else
				{
					list.add(result);
					count++;
				}
			}
		}
		return list.get(0)*1000 + list.get(1)*100 + list.get(2)*10 + list.get(3);
	}
}