公倍数问题

Question

using System;
using System.Collections.Generic;
using System.Text;namespace test3
{
    class Program
    {
        static void Main()
        {
            int a, b;
            int z=1;           
            Console.WriteLine("请输入两个正整数：");
            if (int.TryParse(Console.ReadLine(), out a) && int.TryParse(Console.ReadLine(), out b))
            {
                if (a > b)
                {
                    Cmth.swap(ref a, ref b);
                    for (int i = a; i < 0; i--)
                    {
                        if (a % i == 0 && b % i == 0)
                        {
                            z = i;
                            break;
                        }
                        else
                        {
                            Console.WriteLine("没有公约数!");
                        }
                    }
                    
                }
                Console.WriteLine("最大公约数为:{0}", z);
                Console.WriteLine("最大公倍数为:{0}", a * b / z);
            }
    
        }
    }
    public class Cmth
    { 
        public int x;
        public int y;
        public static void swap(ref int a,ref int b)
        {
            int temp = a;
            a = b;
            b = temp;
        }
    }
 
}//我输出4,6怎么结果不对啊,晕了!

Answer 1

至少这里就是一个错误,改过来再试试吧..
for (int i = a; i < 0; i--)
                    {
                        if (a % i == 0 && b % i == 0)
                        {
                            z = i;
                            break;
                        }
                        else
                        {
                            Console.WriteLine("没有公约数!");
                        }
                    }
将for (int i = a; i < 0; i--)改成for (int i = a; i > 0; i--)

Answer 2

这样改下就OK了: int a, b;
            int z=1;           
            Console.WriteLine("请输入两个正整数：");
            if (int.TryParse(Console.ReadLine(), out a) && int.TryParse(Console.ReadLine(), out b))
            {
                if (a > b)
                {
                    Cmth.swap(ref a, ref b);
                }
                for (int i = a; i > 0; i--)
                {
                    if (a % i == 0 && b % i == 0)
                    {
                        z = i;
                        break;
                    }
                }                    
                Console.WriteLine("最大公约数为:{0}", z);
                Console.WriteLine("最小公倍数为:{0}", a * b / z);
            }测试如下:请输入两个正整数:
4
6
最大公约数为:2
最小公倍数为:12