Catch up on stories from the past week (and beyond) at the Slashdot story archive


Forgot your password?
Check out the new SourceForge HTML5 internet speed test! No Flash necessary and runs on all devices. ×

Lower Limit Found For Sudoku Puzzle Clues 121

ananyo writes "An Irish mathematician has used a complex algorithm and millions of hours of supercomputing time to solve an important open problem in the mathematics of Sudoku, the game popularized in Japan that involves filling in a 9X9 grid of squares with the numbers 1–9 according to certain rules. Gary McGuire of University College Dublin shows in a proof posted online [PDF] that the minimum number of clues — or starting digits — needed to complete a puzzle is 17; puzzles with 16 or fewer clues do not have a unique solution. Most newspaper puzzles have around 25 clues, with the difficulty of the puzzle decreasing as more clues are given."

Slashdot Top Deals

Do not simplify the design of a program if a way can be found to make it complex and wonderful.