1. A configurable apparatus for solving inputted search problems, comprising: a memory having configuration instructions; a hardware system configurable according to said configuration instructions; said configuration instructions configuring said hardware system to perform a search based on a current one of said inputted search problems; and said configuration instructions configuring said hardware system so that, for each of said inputted search problems, backtracking performed during said search includes non-chronological backtracking under control of said hardware system.