title: Shortest string containing all substrings of fixed length(any 1 permutation of the subset) of a list of characters
body: <p>If I am given a list of characters say {s1,s2,s3,...,s10}, I want to find a string of shortest length having all unordered subset combinations of length three occurring as substrings within the string. For example, if I consider the subset { s2, s4, s9 } then I would be able to locate atleast one instance of a string containing those three characters in any order as a substring. There are no repeats, as in it is not required to include a substring of the form 's1s1s1'.</p>