Solving Sudoku
Sudoku is a simple/easy to define problem. You have a 9 x 9 grid and you have to fill the numbers 1 to 9 in such a way that no number is repeated in any row, column, or sub grid. This problem has been explored by a number of people in a number of different ways. Most popular of them all is Peter Norvig’s Solving Every Sudoku Puzzle.