求字符串中重复字符的个数

sample1:"1111222334" output=>3

sample2: "123456" output=>0

C# codes as below:

class Program

{

static void Main(string[] args)

{

Console.WriteLine(GetNumberOfDuplicatedChars("abcd abc ab a"));

Console.ReadKey();

}

static int GetNumberOfDuplicatedChars(string str)

{

int[] intArray = new int[256];

int result = 0;

foreach (char charItem in str)

{

intArray[(int)charItem]++;

}

foreach (int intItem in intArray)

{

if (intItem >= 2)

{

result++;

}

}

return result;

}

}

output:

4