Reverse string in place, wouldn't work for UTF-16

reversestr.cs

public string ReverseWords(string text)
{
	var tarr = text.ToCharArray();
	//reverse the whole string first
	reverse(tarr, 0, tarr.Length-1);
	
	//reverse parts of the string
	int start = 0;
	for(int i = 0; i<tarr.Length; i++)
	{
		if(tarr[i] == ' ')
		{
		  reverse(tarr, start, i -1);
		  while(i < tarr.Length && tarr[i] == ' ')
		  {
		   i++;
		  }
		  start = i;
		}
	}
	
	reverse(tarr,start,tarr.Length-1);
	
	 return new String(tarr);
	}

public static void reverse(char[] text, int start, int end)
{
	if (start == end || start - end == 1)
	        return;

	char tmp;
	int steps = (end-start) / 2;
	int step = 0;
	int i = start;
	int r = end;
	while(step++ <= steps)
	{
		tmp = text[i];
		text[i] = text[r];
		text[r] = tmp;
		i++;
		r--;
	}
}