Given k distinct characters , what is the max length string that can be formed using these characters one or more time so that all the sub-string whose size is greater than one are unique.
Eg - For k = 3 {a,b,c}
A string of max 10 length can be made so that all of its substring whose length is greater than one are unique.(45 sub strings)
String = aabbccacba . Its sub-string of size greater than 2 are
{aa , aab , aabb , aabbc , aabbcc , aabbcca , aabbccac , aabbccacb , aabbccacba , ab , abb , abbc , abbcc , abbcca , abbccac , abbccacb , abbccacba , bb , bbc , bbcc , bbcca , bbccac , bbccacb , bbccacba , bc , bcc , bcca , bccac , bccacb , bccacba , cc , cca , ccac , ccacb , ccacba , ca , cac , cacb , cacba , ac , acb , acba , cb , cba , ba} all of which are unique.