组合数据的输出

排列组合是高中是学到的 知识，理论上很清楚，但如何使用代码实现，却一直没有尝试过，近段时间由于项目需要，写一个组合的算法，想不到却花费了不少时间。

需求很简单，就是典型的组合应用。

例如输入：C0,C1,C2,C3,C4,输出C0,C1,C2,C3,C4的所有组合。

由于输入数据的个数不确定，自然不能使用一般的循环，只能使用递归加循环。

经过不断的实验的和测试，发现有两种实现方法，

  1根据组合长度的输出，例如对于输入C0,C1,C2,C3,C4的五个元素，先输出，一个元素的所有组合，再输出两个元素的所有组合，一次类推，直到所有元素的组合都输出完成。

 具体实现代码：

  public static void CreatSumData2(List<string> columnNameList)
        {
            string res = "";
            // 一个元素
            for (int i = 0; i < columnNameList.Count; i++)//
            {
                string name = columnNameList[i];
                List<string> listContion = new List<string>();
                listContion.Add(name);
                res += OutPutData(listContion);
                listContion.Clear();
            }
            //两个以上元素
            int length = 2;
            int max = columnNameList.Count;//组合的最大元素个数
            while (length <= max)//一直循环到所有元素的组合,每一次循环，处理某一个长度的组合
            {
                for (int i = 0; i <= columnNameList.Count - length + 1; i++)//
                {
                    string name = columnNameList[i];
                    int currentlLvel = i + 1;
                    List<string> hasAddNameList = new List<string>();//保存已添加的元素
                    hasAddNameList.Add(name);
                    res += addOneContion(hasAddNameList, columnNameList, currentlLvel, length);
                    hasAddNameList.Clear();//清空元素
                }
                length++;
            }
            WrieData(res);
        }
        /// <summary>
        /// 添加一个元素
        /// </summary>
        /// <param name="hasAddNameList">已添加的元素</param>
        /// <param name="columnNameList">所有可能的元素</param>
        /// <param name="currentlLvel"></param>
        /// <param name="currentMaxLength">添加的元素的最大个数</param>
        /// <returns></returns>
        private static string addOneContion(List<string> hasAddNameList, List<string> columnNameList, int currentlLvel, int currentMaxLength)
        {
            string res = "";
            bool hasAddOutNames = false;
            int currentlLvelInner = currentlLvel;
            if (hasAddNameList.Count == currentMaxLength)
            {
                res += OutPutData(hasAddNameList);
                hasAddNameList.Clear();
                return res;
            }
            List<string> hasAddNameListInner = new List<string>();
            for (int i = currentlLvelInner; i < columnNameList.Count; i++)//
            {
                string colunmname = columnNameList[i];
                currentlLvelInner++;
                if (!hasAddOutNames)
                {
                    hasAddNameListInner.AddRange(hasAddNameList);
                    hasAddOutNames = true;
                }
                hasAddNameListInner.Add(colunmname);
                if (hasAddNameListInner.Count == currentMaxLength)
                {
                    res += OutPutData(hasAddNameListInner);
                    hasAddNameListInner.Clear();
                    hasAddOutNames = false;
                }
                else
                {
                    res += addOneContion(hasAddNameListInner, columnNameList, currentlLvelInner, currentMaxLength);
                    hasAddNameListInner.Clear();
                    hasAddOutNames = false;
                }
            }
            return res;
        }     

2 根据元素的输出，例如对于输入C0,C1,C2,C3,C4的五个元素，先输出包含C0这个元素的所有组合，再输出包含C1但不包含C0的所有组合，一次类推，直到所有元素的组合都输出完成。

具体实现代码

 public static void CreatSumData(List<string> columnNameList)
        {
            string res = "";
            List<string> hasAddNameList = new List<string>();
            for (int i = 0; i < columnNameList.Count; i++)//
            {
                string colunmname = columnNameList[i];
                int currentlLvel = i;
                currentlLvel++;
                hasAddNameList.Add(colunmname);
                res += OutPutData(hasAddNameList);
                res += CreatNextLevelData(hasAddNameList, columnNameList, currentlLvel);
                hasAddNameList.Clear();

            }
            WrieData(res);
        }
        private static string CreatNextLevelData(List<string> hasAddNameList, List<string> columnNameList, int currentlLvel)
        {
            string res = "";
            List<string> hasAddNameListInner = new List<string>();
            bool hasAddOutNames = false;

            int currentlLvelInner = currentlLvel;
            for (int i = currentlLvelInner; i < columnNameList.Count; i++)//
            {
                if (!hasAddOutNames) {
                    hasAddNameListInner.AddRange(hasAddNameList);
                }
                string colunmname = columnNameList[i];
                currentlLvelInner++;
                hasAddNameListInner.Add(colunmname);
                res += OutPutData(hasAddNameListInner);
                res += CreatNextLevelData(hasAddNameListInner, columnNameList, currentlLvelInner);
                hasAddOutNames = false;
                hasAddNameListInner.Clear();
            }
            return res;
        }

完整的代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;

namespace WindowCeshi
{
    class ZuheTest
    {
        #region 根据组合长度的输出
        public static void CreatSumData2(List<string> columnNameList)
        {
            string res = "";
            // 一个元素
            for (int i = 0; i < columnNameList.Count; i++)//
            {
                string name = columnNameList[i];
                List<string> listContion = new List<string>();
                listContion.Add(name);
                res += OutPutData(listContion);
                listContion.Clear();
            }
            //两个以上元素
            int length = 2;
            int max = columnNameList.Count;//组合的最大元素个数
            while (length <= max)//一直循环到所有元素的组合,每一次循环，处理某一个长度的组合
            {
                for (int i = 0; i <= columnNameList.Count - length + 1; i++)//
                {
                    string name = columnNameList[i];
                    int currentlLvel = i + 1;
                    List<string> hasAddNameList = new List<string>();//保存已添加的元素
                    hasAddNameList.Add(name);
                    res += addOneContion(hasAddNameList, columnNameList, currentlLvel, length);
                    hasAddNameList.Clear();//清空元素
                }
                length++;
            }
            WrieData(res);
        }
        /// <summary>
        /// 添加一个元素
        /// </summary>
        /// <param name="hasAddNameList">已添加的元素</param>
        /// <param name="columnNameList">所有可能的元素</param>
        /// <param name="currentlLvel"></param>
        /// <param name="currentMaxLength">添加的元素的最大个数</param>
        /// <returns></returns>
        private static string addOneContion(List<string> hasAddNameList, List<string> columnNameList, int currentlLvel, int currentMaxLength)
        {
            string res = "";
            bool hasAddOutNames = false;
            int currentlLvelInner = currentlLvel;
            if (hasAddNameList.Count == currentMaxLength)
            {
                res += OutPutData(hasAddNameList);
                hasAddNameList.Clear();
                return res;
            }
            List<string> hasAddNameListInner = new List<string>();
            for (int i = currentlLvelInner; i < columnNameList.Count; i++)//
            {
                string colunmname = columnNameList[i];
                currentlLvelInner++;
                if (!hasAddOutNames)
                {
                    hasAddNameListInner.AddRange(hasAddNameList);
                    hasAddOutNames = true;
                }
                hasAddNameListInner.Add(colunmname);
                if (hasAddNameListInner.Count == currentMaxLength)
                {
                    res += OutPutData(hasAddNameListInner);
                    hasAddNameListInner.Clear();
                    hasAddOutNames = false;
                }
                else
                {
                    res += addOneContion(hasAddNameListInner, columnNameList, currentlLvelInner, currentMaxLength);
                    hasAddNameListInner.Clear();
                    hasAddOutNames = false;
                }
            }
            return res;
        }     

        #endregion
        #region 根据列输出
        public static void CreatSumData(List<string> columnNameList)
        {
            string res = "";
            List<string> hasAddNameList = new List<string>();
            for (int i = 0; i < columnNameList.Count; i++)//
            {
                string colunmname = columnNameList[i];
                int currentlLvel = i;
                currentlLvel++;
                hasAddNameList.Add(colunmname);
                res += OutPutData(hasAddNameList);
                res += CreatNextLevelData(hasAddNameList, columnNameList, currentlLvel);
                hasAddNameList.Clear();

            }
            WrieData(res);
        }
        private static string CreatNextLevelData(List<string> hasAddNameList, List<string> columnNameList, int currentlLvel)
        {
            string res = "";
            List<string> hasAddNameListInner = new List<string>();
            bool hasAddOutNames = false;

            int currentlLvelInner = currentlLvel;
            for (int i = currentlLvelInner; i < columnNameList.Count; i++)//
            {
                if (!hasAddOutNames) {
                    hasAddNameListInner.AddRange(hasAddNameList);
                }
                string colunmname = columnNameList[i];
                currentlLvelInner++;
                hasAddNameListInner.Add(colunmname);
                res += OutPutData(hasAddNameListInner);
                res += CreatNextLevelData(hasAddNameListInner, columnNameList, currentlLvelInner);
                hasAddOutNames = false;
                hasAddNameListInner.Clear();
            }
            return res;
        }
        #endregion
        private static string OutPutData(List<string> listold)
        {
            string text = "";
            for (int i = 0; i < listold.Count; i++)
            {
                string item = listold[i];
                text += "[\"" + item + "\"]";
            }
            return text + "\r\n";
        }
        private static void WrieData(string text)
        {
            string file = "ZuheTestout.js";
            StreamWriter sr = new StreamWriter(file);
            sr.WriteLine(text);
            sr.Close();
        }
    }
}

组合数据的输出