3位数字的递归置换 [英] recursive Permutation of a 3 Digit Number

问题描述

我正在努力递归地查找3位数字的所有排列。

I am working on finding All permutations of a 3-Digit Number recursively.

我厌倦了以下排列方法：

I am tired with making up the following permutation Method:

    static int a = 1;
    static int b = 2;
    static int c = 3;
    static int aCount;
    static int bCount;
    static int cCount;

    static void perm(int a, int b, int c)
    {

        Console.WriteLine("( {0}, {1}, {2} )", a, b, c); // (1,2,3 )

        if (aCount < 1 && bCount<1 &&cCount<1)
        {
            aCount++;

            perm(a, c, b);
        }
        else
            if (aCount==1 && bCount < 1 && cCount<1)
            {

                bCount++;
                perm(b, a, c);
            }
            else
                if (aCount == 1 && bCount == 1 && cCount < 1)
                 {
                    perm(b,c,a);
                  }
        else
                if (aCount==1 && bCount==1 && cCount < 1)
                {
                    cCount++;
                    perm(c, a, b);  //c b a

                }
               else
                    if (aCount == 1 && bCount == 1 &&  cCount == 1)
                {
                    perm(c, b, a);

                }

            }

我试图涵盖所有情况，并在每一步都提供详细信息，但我仍然突然得到堆栈溢出异常。

I tried to Cover ALL cases, with the specifics at each step, and still I get a Stack overflow Exception out of the Blue.

我感谢您的贡献，所以谢谢。

I Appreciate Your Contributions, so Thanks Forwards.

推荐答案

您是说您正在尝试递归，但是所有这些行都出现在您的代码中：

You're saying you're trying recursion, but all those lines appear in your code:

perm(a, c, b)
perm(b, a, c)
perm(b, c, a)
perm(c, a, b)
perm(c, b, a)

当然是函数的第一个调用： perm（a，b，c）

and of course the first call of the function: perm(a, b, c)

这要容易得多要做：

static void perm(int a, int b, int c)
{
    Console.WriteLine("( {0}, {1}, {2} )", a, b, c);
    Console.WriteLine("( {0}, {2}, {1} )", a, b, c);
    Console.WriteLine("( {1}, {0}, {2} )", a, b, c);
    Console.WriteLine("( {1}, {2}, {0} )", a, b, c);
    Console.WriteLine("( {2}, {0}, {1} )", a, b, c);
    Console.WriteLine("( {2}, {1}, {0} )", a, b, c);
}

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