Solving Sudoku Methods Explained
A number game (Sudoku) is a puzzle in which missing numbers are to be filled into a 9 by 9 grid of squares which are subdivided into 3 by 3 boxes so that every row, every column, and every box contains the numbers 1 through 9.
Methods to solve Sudoku puzzles (or Create Sudoku puzzles) include but not limited to:
Basic Solving Sudoku Methods
One-Choice a.k.a Sole Candidate , or Only Candidate , or Naked Single .
Elimination a.k.a Hidden Single , or Loner .
Basic solving sudoku methods do not need you to write down the candidate values for empty squares. Usually very easy or easy Sudoku puzzles can be solved by using basic solving methods.
Advanced Solving Sudoku Methods
Subset2 a.k.a Pair or Naked Pair , or Naked Twins .
SubsetPosition2 a.k.a Hidden Pair or Hidden Twins
Interaction a.k.a Box/Row Claim or Intersection , or Locked Candidates .
Advanced solving sudoku methods need you to write down the candidate values for blank/empty squares. Usually medium, hard, and very hard Sudoku puzzles need to be solved using both basic and advanced solving sudoku methods.
Solve Sudoku - Last Resort
Guessing or Exhaustive Search
a.k.a. Guess-and-check, nishio (Japanese name), or ConflictElimination & Exhaustive Search , or Brute Force
Guessing method needs you to write down the candidate values for blank/empty squares. Usually very hard Sudoku puzzles need to be solved using basic, advanced solving sudoku methods, and guessing method.
Our solver applies methods in the following order:
- Row-Elimination, Column-Elimination, Box-Elimination
- Subset2Row, Subset2Col, Subset2Box
- SubsetPosition2Row, SubsetPosition2Col, SubsetPosition2Box
- Interaction-RowBox, Interaction-ColBox, Interaction-BoxRow, Interaction-BoxCol
- Subset3Row, Subset3Col, Subset3Box, SubsetPosition3Row
- SubsetPosition3Col, SubsetPosition3Box
- Subset4Row, Subset4Col, Subset4Box
- SubsetPosition4Row, SubsetPosition4Col, SubsetPosition4Box
- DoubleRowsOneDigitCheck(X-Wing), DoubleColsOneDigitCheck(X-Wing)
- TripleRowsOneDigitCheck, TripleColsOneDigitCheck
- QuadrRowsOneDigitCheck, QuadrColsOneDigitCheck
- XY-Wing-RowBox, XY-Wing-ColBox, XY-Wing-RowCol
- XYZ-Wing- RowBox, XYZ-Wing-RowBox
- ConflictElimination, Exhaustive Search