Bizon Champion is not bison he favorite Bizons teamAt competition Bizons got follow problem you give distinct word string English letter s t you need transform word s word t the task look simple guy know suffix data structure Bizon Senior love suffix automaton by apply string remove string single character Bizon Middle know suffix array by apply string swap character string the guy know suffix tree help Bizon Champion wonder bizon solve problem perhaps solution require data structure find guy solve problem can solve use suffix automaton use suffix array need structure Note structure unlimited number time structure order