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Challenges Create a Sudoku

BQN, 11 9 bytesSBCS Run online! 1⌽⍟⊢⍋3|↕9 The result is a length 9 list of lists using the numbers 0 to 8. The solution is based on the 3x3 transpose list 036147258, obtained with Grade Up. T...

posted 3y ago by Marshall Lochbaum‭  ·  edited 3y ago by Marshall Lochbaum‭

Answer
#3: Post edited by user avatar Marshall Lochbaum‭ · 2021-06-28T23:28:30Z (almost 3 years ago)
  • # [BQN](https://mlochbaum.github.io/BQN/), 11 bytes<sup>[SBCS](https://github.com/mlochbaum/BQN/blob/master/commentary/sbcs.bqn)</sup>
  • ```
  • 9|+⌜⟜⊐⍋3|↕9
  • ```
  • [Run online!](https://mlochbaum.github.io/BQN/try.html#code=OXwr4oyc4p+c4oqQ4o2LM3zihpU5)
  • Uses the numbers 0 to 8. The result is a 9x9 matrix.
  • Idea is to use the numbers 0 to 8 in order for rows and the 3x3 transpose 036147258 for columns. Adding these in a [table](https://mlochbaum.github.io/BQN/doc/map.html#table) modulo 9 gives a valid solution. [Grade Up](https://mlochbaum.github.io/BQN/doc/order.html#grade) is used to get the transposed sequence and [Classify](https://mlochbaum.github.io/BQN/doc/selfcmp.html#classify) gets the original ordered range back, since all values in the argument are unique.
  • ```
  • 9|+⌜⟜⊐⍋3|↕9
  • ↕9 # Range 0…8
  • 3| # Mod 3: 012012012
  • ⍋ # Grade: 036147258
  • +⌜⟜ # Addition table with…
  • ⊐ # Classify 012345678
  • 9| # Modulo 9
  • ```
  • # [BQN](https://mlochbaum.github.io/BQN/), ~~11~~ 9 bytes<sup>[SBCS](https://github.com/mlochbaum/BQN/blob/master/commentary/sbcs.bqn)</sup>
  • [Run online!](https://mlochbaum.github.io/BQN/try.html#code=MeKMveKNn+KKouKNizN84oaVOQ==)
  • ```
  • 1⌽⍟⊢⍋3|↕9
  • ```
  • The result is a length 9 list of lists using the numbers 0 to 8.
  • The solution is based on the 3x3 transpose list 036147258, obtained with [Grade Up](https://mlochbaum.github.io/BQN/doc/order.html#grade). This list is used to [repeat](https://mlochbaum.github.io/BQN/doc/repeat.html) the operation [rotating](https://mlochbaum.github.io/BQN/doc/reverse.html#rotate) itself by one. Since it's a self-inverse, each subsequent rotation starts it at a number one higher than the previous.
  • ```
  • 1⌽⍟⊢⍋3|↕9
  • ↕9 # Range 0…8
  • 3| # Mod 3: 012012012
  • ⍋ # Grade: 036147258
  • 1⌽ # Rotate by 1
  • ⍟⊢ # Repeated n times for each number n
  • ```
  • ---
  • Previous solution (11): [Run online!](https://mlochbaum.github.io/BQN/try.html#code=OXwr4oyc4p+c4oqQ4o2LM3zihpU5)
  • Idea is to use the numbers 0 to 8 in order for rows and the 3x3 transpose 036147258 for columns. Adding these in a [table](https://mlochbaum.github.io/BQN/doc/map.html#table) modulo 9 gives a valid solution. [Classify](https://mlochbaum.github.io/BQN/doc/selfcmp.html#classify) gets the original ordered range back from the transpose, since all its elements are unique.
  • ```
  • 9|+⌜⟜⊐⍋3|↕9
  • ↕9 # Range 0…8
  • 3| # Mod 3: 012012012
  • ⍋ # Grade: 036147258
  • +⌜⟜ # Addition table with…
  • ⊐ # Classify 012345678
  • 9| # Modulo 9
  • ```
#2: Post edited by user avatar Moshi‭ · 2021-06-28T23:04:00Z (almost 3 years ago)
Index != value (also, challenge has been updated to explicitly allow 0-8)
  • # [BQN](https://mlochbaum.github.io/BQN/), 11 bytes<sup>[SBCS](https://github.com/mlochbaum/BQN/blob/master/commentary/sbcs.bqn)</sup>
  • ```
  • 9|+⌜⟜⊐⍋3|↕9
  • ```
  • [Run online!](https://mlochbaum.github.io/BQN/try.html#code=OXwr4oyc4p+c4oqQ4o2LM3zihpU5)
  • Assumes 0-index; add 1 for 13 bytes if 1-indexed is required. The result is a 9x9 matrix.
  • Idea is to use the numbers 0 to 8 in order for rows and the 3x3 transpose 036147258 for columns. Adding these in a [table](https://mlochbaum.github.io/BQN/doc/map.html#table) modulo 9 gives a valid solution. [Grade Up](https://mlochbaum.github.io/BQN/doc/order.html#grade) is used to get the transposed sequence and [Classify](https://mlochbaum.github.io/BQN/doc/selfcmp.html#classify) gets the original ordered range back, since all values in the argument are unique.
  • ```
  • 9|+⌜⟜⊐⍋3|↕9
  • ↕9 # Range 0…8
  • 3| # Mod 3: 012012012
  • ⍋ # Grade: 036147258
  • +⌜⟜ # Addition table with…
  • ⊐ # Classify 012345678
  • 9| # Modulo 9
  • ```
  • # [BQN](https://mlochbaum.github.io/BQN/), 11 bytes<sup>[SBCS](https://github.com/mlochbaum/BQN/blob/master/commentary/sbcs.bqn)</sup>
  • ```
  • 9|+⌜⟜⊐⍋3|↕9
  • ```
  • [Run online!](https://mlochbaum.github.io/BQN/try.html#code=OXwr4oyc4p+c4oqQ4o2LM3zihpU5)
  • Uses the numbers 0 to 8. The result is a 9x9 matrix.
  • Idea is to use the numbers 0 to 8 in order for rows and the 3x3 transpose 036147258 for columns. Adding these in a [table](https://mlochbaum.github.io/BQN/doc/map.html#table) modulo 9 gives a valid solution. [Grade Up](https://mlochbaum.github.io/BQN/doc/order.html#grade) is used to get the transposed sequence and [Classify](https://mlochbaum.github.io/BQN/doc/selfcmp.html#classify) gets the original ordered range back, since all values in the argument are unique.
  • ```
  • 9|+⌜⟜⊐⍋3|↕9
  • ↕9 # Range 0…8
  • 3| # Mod 3: 012012012
  • ⍋ # Grade: 036147258
  • +⌜⟜ # Addition table with…
  • ⊐ # Classify 012345678
  • 9| # Modulo 9
  • ```
#1: Initial revision by user avatar Marshall Lochbaum‭ · 2021-06-28T22:01:45Z (almost 3 years ago)
# [BQN](https://mlochbaum.github.io/BQN/), 11 bytes<sup>[SBCS](https://github.com/mlochbaum/BQN/blob/master/commentary/sbcs.bqn)</sup>

```
9|+⌜⟜⊐⍋3|↕9
```

[Run online!](https://mlochbaum.github.io/BQN/try.html#code=OXwr4oyc4p+c4oqQ4o2LM3zihpU5)

Assumes 0-index; add 1 for 13 bytes if 1-indexed is required. The result is a 9x9 matrix.

Idea is to use the numbers 0 to 8 in order for rows and the 3x3 transpose 036147258 for columns. Adding these in a [table](https://mlochbaum.github.io/BQN/doc/map.html#table) modulo 9 gives a valid solution. [Grade Up](https://mlochbaum.github.io/BQN/doc/order.html#grade) is used to get the transposed sequence and [Classify](https://mlochbaum.github.io/BQN/doc/selfcmp.html#classify) gets the original ordered range back, since all values in the argument are unique.

```
9|+⌜⟜⊐⍋3|↕9
         ↕9  # Range 0…8
       3|    # Mod 3: 012012012
      ⍋      # Grade: 036147258
  +⌜⟜        # Addition table with…
     ⊐       #   Classify 012345678
9|           # Modulo 9
```