求高手排列组合算法

[99guo]

例如下面的例子：
数组1: "S1","S2","S3"
数组2: "B2"
数组3: "C1","C2"
得到结果 "S1,B2,C1"，"S1,B2,C2"，“S2,B2,C1”，“S2,B2,C2”，"S3,B2,C1","S3,B2,C2"

我想得到上面的所有排列组合算法，求大神有没方法，如何做？？

[99guo]

引用 2 楼 uinatlex 的回复:

笛卡尔积 会不 初中该毕业了吧 List<string> A = new List<string> { "S1", "S2", "S3" }; List<string> B = new List<string> { "B2" }; List<string> C = new List<string> { "C1", "C2" }; IEnumerable<string> result = from a in A from b in B from c in C select a + b + c;

这个方法是不错，但问题是数组不限于3层，可能N层。

[yzf86211861]

看大神来表演了 。

[adawoo]

坐等大神！

[uinatlex]

引用 3 楼 99guo 的回复:

[quote=引用 2 楼 uinatlex 的回复:] 笛卡尔积 会不 初中该毕业了吧 List<string> A = new List<string> { "S1", "S2", "S3" }; List<string> B = new List<string> { "B2" }; List<string> C = new List<string> { "C1", "C2" }; IEnumerable<string> result = from a in A from b in B from c in C select a + b + c;

这个方法是不错，但问题是数组不限于3层，可能N层。[/quote] 笛卡尔积就是不停的乘 你无限还不是乘，递归就完了

        List<string> RecursionLINQ(List<string[]> list, int startCount, List<string> result)
        {
            if (startCount < list.Count)
            {
                result = result.Count == 0 ?
                    (from b in list[startCount] select b).ToList() :
                    (from a in result from b in list[startCount] select a + b).ToList();

                result = RecursionLINQ(list, startCount + 1, result);
            }

            return result;
        }


            string[] strs1 = { "S1", "S2", "S3" };
            string[] strs2 = { "B2" };
            string[] strs3 = { "C1", "C2" };
            List<string[]> list = new List<string[]>();

            list.Add(strs1);
            list.Add(strs2);
            list.Add(strs3);

            List<string> result = new List<string>();

           result = RecursionLINQ(list, 0, result);

[淡淡的活着]

套三循环······

[threenewbee]

http://bbs.csdn.net/topics/390572575 看我的回答

[uinatlex]

笛卡尔积 会不 初中该毕业了吧 List<string> A = new List<string> { "S1", "S2", "S3" }; List<string> B = new List<string> { "B2" }; List<string> C = new List<string> { "C1", "C2" }; IEnumerable<string> result = from a in A from b in B from c in C select a + b + c;

[游离失所]

都弱爆了。。看我的。。

      List<string> A = new List<string> { "S1", "S2", "S3" };
            List<string> B = new List<string> { "B2" };
            List<string> C = new List<string> { "C1", "C2" };
            List<List<string>> list = new List<List<string>>()
            {
                A,
                B,
                C
            };
            var result = list.Aggregate((thisCurrent, nextCurrent) => thisCurrent.SelectMany(x => nextCurrent.Select(y => y + x)).ToList());
            foreach (var temp in result)
            {
                Response.Write(temp + "<br/>");
            }

[insus]

引用 9 楼 lyj224170707 的回复:

都弱爆了。。看我的。。

      List<string> A = new List<string> { "S1", "S2", "S3" };
            List<string> B = new List<string> { "B2" };
            List<string> C = new List<string> { "C1", "C2" };
            List<List<string>> list = new List<List<string>>()
            {
                A,
                B,
                C
            };
            var result = list.Aggregate((thisCurrent, nextCurrent) => thisCurrent.SelectMany(x => nextCurrent.Select(y => y + x)).ToList());
            foreach (var temp in result)
            {
                Response.Write(temp + "<br/>");
            }

如果数组B的值有些变化： List<string> B = new List<string> { "B2" ,"B3"}; 再测试一下你的代码，不知所得的结果是否也是lz想要的结果？

[游离失所]

引用 10 楼 insus 的回复:

[quote=引用 9 楼 lyj224170707 的回复:] 都弱爆了。。看我的。。

      List<string> A = new List<string> { "S1", "S2", "S3" };
            List<string> B = new List<string> { "B2" };
            List<string> C = new List<string> { "C1", "C2" };
            List<List<string>> list = new List<List<string>>()
            {
                A,
                B,
                C
            };
            var result = list.Aggregate((thisCurrent, nextCurrent) => thisCurrent.SelectMany(x => nextCurrent.Select(y => y + x)).ToList());
            foreach (var temp in result)
            {
                Response.Write(temp + "<br/>");
            }

如果数组B的值有些变化： List<string> B = new List<string> { "B2" ,"B3"}; 再测试一下你的代码，不知所得的结果是否也是lz想要的结果？ [/quote] C1B2S1 C2B2S1 C1B3S1 C2B3S1 C1B2S2 C2B2S2 C1B3S2 C2B3S2 C1B2S3 C2B2S3 C1B3S3 C2B3S3 这是加上B3后的运行结果