A Challenging String-Manipulation Project

(A Crossword Puzzle Generator) Most people have worked a crossword puzzle, but few have ever attempted to generate one. Generating a crossword puzzle is a difficult problem. It is suggested here as a string-manipulation project requiring substantial sophistication and effort. There are many issues that the programmer must resolve to get even the simplest crossword puzzle generator program working. For example, how does one represent the grid of a crossword puzzle inside the computer? Should one use a series of strings, or should two-dimensional arrays be used? The programmer needs a source of words (i.e., a computerized dictionary) that can be directly referenced by the program. In what form should these words be stored to facilitate the complex manipulations required by the program? The really ambitious reader will want to generate the "clues" portion of the puzzle, in which the brief hints for each "across" word and each "down" word are printed for the puzzle worker. Merely printing a version of the blank puzzle itself is not a simple problem.