public int MaxLength(IList <string> arr)
{
if (arr == null || arr.Count == 0)
{
return(0);
}
var filteredArray = arr.Where(x => x.Distinct().Count() == x.Length).ToArray();
if (filteredArray.Length == 0)
{
return(0);
}
int totalUniqueChars = filteredArray.SelectMany(x => x.ToCharArray()).Distinct().Count();
var soln = new SolnDS();
this.MaxLengthHelper(filteredArray, soln, totalUniqueChars);
return(soln.maxLength);
}
public void MaxLengthHelper(IList <string> currentArray, SolnDS soln, int TotalUniqueChars)
{
foreach (var item in currentArray)
{
if (soln.IsSafe(item))
{
soln.Add(item);
if (soln.maxLength == TotalUniqueChars)
{
return;
}
this.MaxLengthHelper(currentArray, soln, TotalUniqueChars);
}
// try next one.
}
// pop previous addition.
soln.Remove();
}
