Puzzle: There are 100 doors in a long hallway. They are all closed. The first time you walk by each door, you open it. The second time around, you close every second door (since they are all opened). On the third pass you stop at every third door and ...

In computing, memoization is an optimization technique used primarily to speed up computer programs by storing the results of expensive function calls and returning the cached result when the same inputs occur again. Memoization has also been used in ...

The eight queens puzzle is the problem of placing eight chess queens on an 88 chessboard so that no two queens threaten each other. Thus, a solution requires that no two queens share the same row, column, or diagonal. The eight queens puzzle is an ...

The numeric system represented by Roman numerals originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the late Middle Ages. Numbers in this system are represented by combinations of letters from the Latin ...