Random Noise

September 27, 2008

RotateString v2.0

Filed under: .NET — Tags: , — Vivek Unune @ 4:46 pm

I added the ability to rotate string right or left. Here is the code:


public enum Direction { Right, Left }

string rotateString(string source, int rotationCount, Direction direction)
{
    if (String.IsNullOrEmpty(source) || rotationCount <= 0)
        return source;

    int pivot = 0;
    List<int> delimiterLocations = new List<int>();
    char[] sourceChars = new char;

    char temp;
    // Reverse the whole string and
    // save the dilimiter locations
    for (int i = 0; i < source.Length; i++)
    {
        sourceChars = source[i];

        if (source[i] == ' ')
            delimiterLocations.Add(source.Length - i - 1);
    }

    // calculate neededDelimiters mod wordCount
    // (assume words = delimiterCount + 1)
    pivot = rotationCount % delimiterLocations.Count;

    if (pivot > 0)
    {
        if (direction == Direction.Left)
            pivot = delimiterLocations.Count - pivot;

        pivot = delimiterLocations[delimiterLocations.Count - pivot];
    }
    else
    { return source; }

    // reverse the first part
    for (int i = 0, j = pivot - 1; i <= j; i++, j--)
    {
        temp = sourceChars[i];
        sourceChars[i] = sourceChars[j];
        sourceChars[j] = temp;
    }

    // reverse the second part
    for (int i = pivot + 1, j = sourceChars.Length - 1;
         i <= j; i++, j--)
    {
        temp = sourceChars[i];
        sourceChars[i] = sourceChars[j];
        sourceChars[j] = temp;
    }

    return new string(sourceChars);
}

No Comments Yet »

No comments yet.

RSS feed for comments on this post. TrackBack URI

Leave a comment

Blog at WordPress.com.