刚看到网上一篇文章里用sql实现了行列转置。sql server 2005/2008只用一个pivot函数就可以实现sql server 2000很多行的复杂实现。提到转置，立刻想起还在求学阶段曾经做过的一个练习，用c语言实现二维数组的转置。相信大家都做过这个练习。下面利用c#利器也实现一遍，没有实际意义，练练手而已。
1、二维数组转置
Code class Program { public static string[,] Rotate(string[,] array) { int x = array.GetUpperBound(0); //一维 int y = array.GetUpperBound(1); //二维 string[,] newArray = new string[y + 1, x + 1]; //构造转置二维数组 for (int i = 0; i <= x; i++) { for (int j = 0; j <= y; j++) { newArray[j, i] = array[i, j]; } } return newArray; } static void Main(string[] args) { string[,] array = new string[4, 2]; for (int i = 0; i < 4; i++) { for (int j = 0; j < 2; j++) { array[i, j] = i.ToString() + j.ToString(); } } //显示原数组 Console.WriteLine("Source Array:"); for (int i = 0; i < 4; i++) { string soureResult = string.Empty; for (int j = 0; j < 2; j++) { soureResult += array[i, j] + " "; } Console.WriteLine(soureResult); } string[,] newArray = Rotate(array); //显示转置后的数组 Console.WriteLine("Destiney Array:"); for (int i = 0; i < 2; i++) { string dstResult = string.Empty; for (int j = 0; j < 4; j++) { dstResult += newArray[i, j] + " "; } Console.WriteLine(dstResult); } Console.ReadLine(); } }
2、二维数组列表List<>的转置
这个是想到在实际项目中操作集合经常用到泛型List，顺便实现一下它的转置。思路很简单，根据1，我们已经实现了转置，所以就要想方设法把泛型List转换成二维数组，然后转置，接着将转换后的数组再转换成泛型List。呵呵，笔者偷懒惯了，其实应该还有其他的方法，不管了，先实现看下效果。
Code class Program { /// <summary> /// 二维数组转置函数 /// </summary> /// <param name="array"></param> /// <returns></returns> public static string[,] Rotate(string[,] array) { int x = array.GetUpperBound(0); //一维 int y = array.GetUpperBound(1); //二维 string[,] newArray = new string[y + 1, x + 1]; //构造转置二维数组 for (int i = 0; i <= x; i++) { for (int j = 0; j <= y; j++) { newArray[j, i] = array[i, j]; } } return newArray; } /// <summary> /// 将二维列表(List)转换成二维数组，二维数组转置，然后将二维数组转换成列表 /// </summary> /// <param name="original"></param> /// <returns></returns> public static List<List<string>> Rotate(List<List<string>> original) { List<string>[] array = original.ToArray(); List<List<string>> lists = new List<List<string>>(); if (array.Length==0) { throw new IndexOutOfRangeException("Index OutOf Range"); } int x = array[0].Count; int y = original.Count; //将列表抓换成数组 string[,] twoArray = new string[y, x]; for (int i = 0; i < y; i++) { int j = 0; foreach (string s in array[i]) { twoArray[i, j] = s; j++; } } string[,] newTwoArray = new string[x, y]; newTwoArray = Rotate(twoArray);//转置 //二维数组转换成二维List集合 for (int i = 0; i < x; i++) { List<string> list = new List<string>(); for (int j = 0; j < y; j++) { list.Add(newTwoArray[i, j]); } lists.Add(list); } return lists; } static void Main(string[] args) { List<List<string>> sourceList = new List<List<string>>(); //测试的二维List for (int i = 0; i < 4; i++) { List<string> list = new List<string>(); for (int j = 0; j < 2; j++) { list.Add(i.ToString() + j.ToString()); } sourceList.Add(list); } //显示原列表 Console.WriteLine("Source List:"); for (int i = 0; i < sourceList.Count; i++) { string soureResult = string.Empty; for (int j = 0; j < sourceList[i].Count; j++) { soureResult += sourceList[i][j] + " "; } Console.WriteLine(soureResult); } List<List<string>> dstList = Rotate(sourceList); //显示转置后的列表 Console.WriteLine("Destiney List:"); for (int i = 0; i < dstList.Count; i++) { string dstResult = string.Empty; for (int j = 0; j < dstList[i].Count; j++) { dstResult += dstList[i][j] + " "; } Console.WriteLine(dstResult); } Console.ReadLine(); } }