Crossword Grid Symmetry Checker
Actualblack/whitecrosswordmask180°rotational-symmetrycheck,no cluefillcorrectness or allcrosswordstyles requirement. Boundedoffline arithmetic/sampling only;not gambling advice,fair physical randomness,secure randomness or predictive certainty.
Description
A crossword’s black-square pattern has 180-degree rotational symmetry when turning it upside down leaves the pattern unchanged.
A crossword’s black-square pattern has 180-degree rotational symmetry when turning it upside down leaves the pattern unchanged.1
This checker compares a supplied binary grid; it does not check clue quality, connectivity or a publisher’s complete layout rules.
When to use Crossword Grid Symmetry Checker
Use this tool to apply the stated crossword grid symmetry checker operation with an explicit input and unit basis.
How to use Crossword Grid Symmetry Checker and how it works
- Establish the text or game convention described above.
- Enter actualBlackCellGrid and run the tool.
- Read result.hasRotational180Symmetry using the output meanings below.
- If input is rejected, correct the stated type, range, ordering or alignment issue and rerun; review successful results under the declared convention.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| actualBlackCellGrid | Black Cell Grid. Units, ordering and applicable branch are specified in the algorithm. | array of array of number | required; dense; align related rows as specified; further conditions in the algorithm |
Require a nonempty rectangular matrix containing only 0 and 1. Compare each cell with the cell at reversed row and column indices; return false on any disagreement and true otherwise.
grid[r][c] = grid[height−1−r][width−1−c] for every cell Apply the declared units, ordering and branch conditions.
| Output field | Meaning | Value type |
|---|---|---|
| result | Object containing the declared output fields. | object |
| result.hasRotational180Symmetry | True when every binary cell equals its 180-degree counterpart. | boolean |
{
"input": {
"actualBlackCellGrid": [
[
1,
0
],
[
0,
1
]
]
},
"output": {
"result": {
"hasRotational180Symmetry": true
}
}
}Limitations and assumptions
The output applies the declared operation to the values you supply. Establish the measurement basis, units, coefficients and any caller-selected rules before interpreting it. The tool does not independently collect or verify observations or decide whether a model or reference applies.
Supply explicit required fields with the documented types and dense aligned arrays. Unknown fields, wrong types and nonfinite numbers are rejected. Branch-specific constraints are explained above. A returned boolean, signed difference or tied result follows the stated convention; an input error instead means the required input contract was not satisfied. Very large inputs or outputs may be rejected by shared resource limits.
Alternative or Complementary methods
For a related operation, use Chess Puzzle FEN Validator. Forsyth–Edwards Notation represents a chess position with six fields for pieces, turn, castling, en passant and move counters.
For a related operation, use Chess Opening Name Lookup. Chess opening references depend on move order, notation, transpositions and the chosen classification edition.
References
-
Crossword Grid Symmetry Checker — tool.io
Similar or alternative tools
- Chess Puzzle FEN Validator
Forsyth–Edwards Notation represents a chess position with six fields for pieces, turn, castling, en passant and move counters.
- Chess Opening Name Lookup
Chess opening references depend on move order, notation, transpositions and the chosen classification edition.