刚看到网上一篇博文里用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
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。
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();
}
}
来自：http://www.cnblogs.com/wjfluisfigo/archive/2009/11/15/1603130.html