# The Sudoku Program

## How does the program solve Sudoku puzzles?

Our Sudoku solvers use some of the most advanced logic to solve Sudoku puzzles. Here, we have outlined the general method used to solve all Sudoku puzzles.

### Starting assumption

For each unsolved square, the program initially assumes that there is a solution from any of the numbers 1-9 for a Sudoku and Samurai Sudoku puzzles, 0-9, A-F for Super Sudoku or nine letters for a Godoku puzzle.

### Reducing choices

The program looks at each square in the grid and for each one it removes other numbers in the same row, column and box from the list of possible solutions. It also uses other methods; similar to the methods a person might use to solve it, to reduce the number of possibilities for each square.

### Solution for a square

When a square has only one possible solution remaining, the square is solved.

### Groups

The program creates arrays of groups and patterns of numbers in order to eliminate the further possibilities throughout the grid. Easy and moderate difficulty Sudoku puzzles should not require these checks.

### Guessing

On rare occasions, valid Sudoku puzzles cannot be completed without “guessing” a possible solution. If the program cannot solve a square, it makes a guess. The program logically selects the best place to make a guess, making more guesses if required, until the program can continue solving squares using the normal methods. Sudoku puzzles that need guessing very often require more than logic in order to solve the puzzle and may have non-unique solutions. For this reason, some Sudoku solvers do not perform guesses at all.

### Done

The results display along with other information such as the number of guesses it required.

## About the Sudoku generator

Our Sudoku puzzles are generated using the same logic used by the Sudoku solver.

### Sudoku power

The Sudoku generator at *Prize Sudoku* is very powerful indeed. It can create any level of difficulty Sudoku, Super Sudoku or Samurai Sudoku in an extremely short time-span.

Our Sudokus cannot be matched by human generating in terms of interest of solving and no Sudoku program can match the speed and complexity of the *Prize Sudoku* generator.

### Valid Sudoku

The Sudoku, Super Sudoku or Samurai Sudoku puzzles are generated to a specific difficulty level and then verified by the number of solving loops and levels of logic.

All our Sudoku can be solved with logic that be replicated by a human, guessing is never a necessity. This ensures that our Sudoku puzzles have one unique solution.

### Original Sudoku

Sudoku puzzles are generated in a completely random manner ensuring that it is virtually impossible that any two puzzles will be the same.