What is the minimum number of clues for Sudoku?

The fewest clues required for a proper Sudoku is 17, but not all completed grids can be reduced to a proper 17 clue Sudoku. About 49,000 unique (non-equivalent) Sudokus with 17 clues have been found. (A proper Sudoku has only one solution).

What is a minimal Sudoku?

A proper puzzle has a unique solution. A minimal puzzle is a proper puzzle from which no clue can be removed without introducing additional solutions. See Glossary of Sudoku for other terminology.

Is 0 allowed in Sudoku?

Binary Sudoku is a variant that only allows the numbers 0 and 1. The rules are as follows. Each row and each column must contain an equal number of zeros and ones.

Can a Sudoku have more than one solution?

A well-formed Sudoku puzzle is one that has a unique solution. A Sudoku puzzle can have more than one solution, but in this case the kind of logical reasoning we described while discussing solving strategies may fall short. There are examples of rank-3 Sudoku puzzles with 17 givens that are well-formed.

What is Sudoku 3×3?

A 3×3 box is a group of nine cells three cells wide and three cells high as shown by the two large teal squares in Figure 1. The nine 3×3 boxes in a sudoku puzzle are delineated by the bold lines.

Can a Sudoku be unsolvable?

These hard puzzles may seem ‘unsolvable’ to all but the committed Sudoku expert. We sometimes receive puzzles that our users consider ‘unsolvable’, but with a bit of study they can usually be solved.

How to talk about sudoku on the Internet?

Choose a number, and place it in the grid above. Welcome to the Sudoku Forums! Talk about anything and everything, but place your comments in the right categories so that people on slow internet connections can still enjoy the site. Also, be nice to each other – you don’t have to agree, but this is not the place for personal attacks.

How to play Sudoku as a jigsaw puzzle?

Play this pic as a Jigsaw or Sliding Puzzle. Choose a number, and place it in the grid above. Welcome to the Sudoku Forums! Talk about anything and everything, but place your comments in the right categories so that people on slow internet connections can still enjoy the site.

How is the min conflicts algorithm used in Computer Science?

In computer science, the min conflicts algorithm is a search algorithm or heuristic method to solve constraint satisfaction problems (CSP). Given an initial assignment of values to all the variables of a CSP, the algorithm randomly selects a variable from the set of variables with conflicts violating one or more constraints of the CSP.

How is min conflicts used for hard problems?

It is also effective for hard problems. For example, it has been used to schedule observations for the Hubble Space Telescope, reducing the time taken to schedule a week of observations from three weeks to around 10 minutes. ^ Minton, Steven; Mark D. Johnston; Andrew B. Philips; Philip Laird (1990).