找出字符串的最长子串（可能不止一个），要求子串的所有字符相同，如："abcdeeefgh"结果是"eee"...

如题，C# Code如下：

public static string[] GetBiggestString(string str)

{

if (str == null || str == string.Empty)

{

throw new Exception("Null or empty!!!!");

}

var max = 1;

var count = 1;

var number = 0;

char[] theChar=new char[str.Length];

theChar[number] = str[0];

for (int i = 1; i < str.Length; i++)

{

if (str[i] == str[i - 1])

{

count++;

if(max < count)

{

max=count;

number = 0;

theChar[number]=str[i];

}

else if (max == count)

{

number++;

theChar[number] = str[i];

}

}

if (str[i] != str[i - 1])

{

count = 1;

}

}

string[] strArray = new string[number+1];

for (int i = 0; i <= number; i++)

{

strArray[i] = new string(theChar[i], max);

}

return strArray;

}