You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
|
|
|
|
# Sudoku verifier
|
|
|
|
|
|
|
|
|
|
## Definition
|
|
|
|
|
Sudokus are logic number puzzles in which cells in a 9×9 grid must be populated with
|
|
|
|
|
the digits 1 to 9 in a way that each digit occurrs only once in each unit (that is column,
|
|
|
|
|
row or block = 3×3 sub grid).
|
|
|
|
|
|
|
|
|
|
![a solved simple sudoku](sudoku.gif)
|
|
|
|
|
|
|
|
|
|
## Goal
|
|
|
|
|
Validate if a given solution for a Sudoku is valid, by checking that the digit
|
|
|
|
|
1 to 9 appear only once in column, in each row and in each of the 9 sub grids.
|
|
|
|
|
|
|
|
|
|
### Input
|
|
|
|
|
a sequence of 81 digits, organized in 9 columns and 9 rows
|
|
|
|
|
|
|
|
|
|
### Output
|
|
|
|
|
A boolean value, if the grid is valid.
|
|
|
|
|
|
|
|
|
|
### Constraints
|
|
|
|
|
1 <= `digit` <= 9
|
|
|
|
|
|
|
|
|
|
### Examples
|
|
|
|
|
**Input:**
|
|
|
|
|
```
|
|
|
|
|
9 8 1 5 2 3 6 4 7
|
|
|
|
|
6 3 4 8 7 9 2 5 1
|
|
|
|
|
2 7 5 1 4 6 9 8 3
|
|
|
|
|
1 9 6 4 8 7 5 3 2
|
|
|
|
|
5 4 8 3 1 2 7 6 9
|
|
|
|
|
7 2 3 6 9 5 4 1 8
|
|
|
|
|
3 1 2 7 5 4 8 9 6
|
|
|
|
|
4 6 9 2 3 8 1 7 5
|
|
|
|
|
8 5 7 9 6 1 3 2 4
|
|
|
|
|
```
|
|
|
|
|
**Output:**
|
|
|
|
|
`true`
|