Find common prefix of strings

Question

I am having 4 strings:

"h:/a/b/c"
"h:/a/b/d"
"h:/a/b/e"
"h:/a/c"

I want to find the common prefix for those strings, i.e. "h:/a". How to find that?

Usually I'd split the string with delimiter '/' and put it in another list, and so on.
Is there any better way to do it?

Answer 1

string[] xs = new[] { "h:/a/b/c", "h:/a/b/d", "h:/a/b/e", "h:/a/c" };

string x = string.Join("/", xs.Select(s => s.Split('/').AsEnumerable())
                              .Transpose()
                              .TakeWhile(s => s.All(d => d == s.First()))
                              .Select(s => s.First()));

with

public static IEnumerable<IEnumerable<T>> Transpose<T>(
    this IEnumerable<IEnumerable<T>> source)
{
    var enumerators = source.Select(e => e.GetEnumerator()).ToArray();
    try
    {
        while (enumerators.All(e => e.MoveNext()))
        {
            yield return enumerators.Select(e => e.Current).ToArray();
        }
    }
    finally
    {
        Array.ForEach(enumerators, e => e.Dispose());
    }
}