a11y note: To make it look more colorful, everything is syntax highlighted in other languages. They're all .txt files though. The files themselves are also mostly unimportant.
Sudoku can be represented as this huge node graph coloring problem
Every cell is connected to many other cells, and has a few possibilities (candidates)
And here's even more abstraction:
Each candidate is either on or off. TRUE or FALSE
So instead of "cells" (so unnecessary) why not just list all the candidates and their connections?
Here's a basic partial list of all the candidates and their connections.
First up, A1: candidate 1, aka A1=1
A1=1
Part 1 (cell)
A1=2
A1=3
A1=4
A1=5
A1=6
A1=7
A1=8
A1=9
Part 2 (row)
A2=1
A3=1
A4=1
A5=1
A6=1
A7=1
A8=1
A9=1
Part 3 (column)
B1=1
C1=1
D1=1
E1=1
F1=1
G1=1
H1=1
J1=1
Part 4 (box)
A2=1
A3=1
B1=1
B2=1
B3=1
C1=1
C2=1
C3=1
Connections
any of (Part 1, Part 2, Part 3, Part 4) -> FALSE
none of (Part 1) -> TRUE
none of (Part 2) -> TRUE
none of (Part 3) -> TRUE
none of (Part 4) -> TRUEOk, that's the end of the partial list.
Wayy too long!
(Unless you're a computer.)
But at least the list can be simplified as candidates are removed.
Let's look at the Easter Monster sudoku
1.......2
.9.4...5.
..6...7..
.5.9.3...
....7....
...85..4.
7.....6..
.3...9.8.
..2.....1After simple candidate removal we get:
+----------------------+----------------------+----------------------+
| 1 478 34578 | 3567 3689 5678 | 3489 369 2 |
| 238 9 378 | 4 12368 12678 | 138 5 368 |
| 23458 248 6 | 1235 12389 1258 | 7 139 3489 |
+----------------------+----------------------+----------------------+
| 2468 5 1478 | 9 1246 3 | 128 1267 678 |
| 234689 12468 13489 | 126 7 1246 | 123589 12369 35689 |
| 2369 1267 1379 | 8 5 126 | 1239 4 3679 |
+----------------------+----------------------+----------------------+
| 7 148 14589 | 1235 12348 12458 | 6 239 3459 |
| 456 3 145 | 12567 1246 9 | 245 8 457 |
| 45689 468 2 | 3567 3468 45678 | 3459 379 1 |
+----------------------+----------------------+----------------------+The thing is, once we've already written down all the possibilities and connections;
after the simple candidate removal, we don't care about the solved cells anymore.
Here are the candidates in the Easter Monster
A1=1: TRUE
A1=2: FALSE
A1=3: FALSE
A1=4: FALSE
A1=5: FALSE
A1=6: FALSE
A1=7: FALSE
A1=8: FALSE
A1=9: FALSE
A2=1: FALSE
A2=2: $1
A2=3: $2
A2=4: FALSE
A2=5: FALSE
A2=6: FALSE
A2=7: FALSE
A2=8: $3
A2=9: FALSE
A3=1: FALSE
A3=2: $4
A3=3: $5
A3=4: $6
A3=5: $7
A3=6: FALSE
A3=7: FALSE
A3=8: $8
A3=9: FALSE
A4=1: FALSE
A4=2: $
A4=3: FALSE
A4=4: $
A4=5: FALSE
A4=6: $
A4=7: FALSE
A4=8: $
A4=9: FALSE
A5=1: FALSE
A5=2: $
A5=3: $
A5=4: $
A5=5: FALSE
A5=6: $
A5=7: FALSE
A5=8: $
A5=9: $
A6=1: FALSE
A6=2: $
A6=3: $
A6=4: FALSE
A6=5: FALSE
A6=6: $
A6=7: FALSE
A6=8: FALSE
A6=9: $
A7=1: FALSE
A7=2: FALSE
A7=3: FALSE
A7=4: FALSE
A7=5: FALSE
A7=6: FALSE
A7=7: TRUE
A7=8: FALSE
A7=9: FALSE
A8=1: FALSE
A8=2: FALSE
A8=3: FALSE
A8=4: $
A8=5: $
A8=6: $
A8=7: FALSE
A8=8: FALSE
A8=9: FALSE
A9=1: FALSE
A9=2: FALSE
A9=3: FALSE
A9=4: $
A9=5: $
A9=6: $
A9=7: FALSE
A9=8: $
A9=9: $
B1=1: FALSE
B1=2: FALSE
B1=3: FALSE
B1=4: $
B1=5: FALSE
B1=6: FALSE
B1=7: $
B1=8: $
B1=9: FALSE
B2=1: FALSE
B2=2: FALSE
B2=3: FALSE
B2=4: FALSE
B2=5: FALSE
B2=6: FALSE
B2=7: FALSE
B2=8: FALSE
B2=9: TRUE
B3=1: FALSE
B3=2: $
B3=3: FALSE
B3=4: $
B3=5: FALSE
B3=6: FALSE
B3=7: FALSE
B3=8: $
B3=9: FALSE
B4=1: FALSE
B4=2: FALSE
B4=3: FALSE
B4=4: FALSE
B4=5: TRUE
B4=6: FALSE
B4=7: FALSE
B4=8: FALSE
B4=9: FALSE
B5=1: $
B5=2: $
B5=3: FALSE
B5=4: $
B5=5: FALSE
B5=6: $
B5=7: FALSE
B5=8: $
B5=9: FALSE
B6=1: $
B6=2: $
B6=3: FALSE
B6=4: FALSE
B6=5: FALSE
B6=6: $
B6=7: $
B6=8: FALSE
B6=9: FALSE
B7=1: $
B7=2: FALSE
B7=3: FALSE
B7=4: $
B7=5: FALSE
B7=6: FALSE
B7=7: FALSE
B7=8: $
B7=9: FALSE
B8=1: FALSE
B8=2: FALSE
B8=3: TRUE
B8=4: FALSE
B8=5: FALSE
B8=6: FALSE
B8=7: FALSE
B8=8: FALSE
B8=9: FALSE
B9=1: FALSE
B9=2: FALSE
B9=3: FALSE
B9=4: $
B9=5: FALSE
B9=6: $
B9=7: FALSE
B9=8: $
B9=9: FALSE
C1=1: FALSE
C1=2: FALSE
C1=3: FALSE
C1=4: FALSE
C1=5: FALSE
C1=6: FALSE
C1=7: FALSE
C1=8: FALSE
C1=9: FALSE
C2=1: FALSE
C2=2: FALSE
C2=3: FALSE
C2=4: FALSE
C2=5: FALSE
C2=6: FALSE
C2=7: FALSE
C2=8: FALSE
C2=9: FALSE
C3=1: FALSE
C3=2: FALSE
C3=3: FALSE
C3=4: FALSE
C3=5: FALSE
C3=6: FALSE
C3=7: FALSE
C3=8: FALSE
C3=9: FALSE
C4=1: FALSE
C4=2: FALSE
C4=3: FALSE
C4=4: FALSE
C4=5: FALSE
C4=6: FALSE
C4=7: FALSE
C4=8: FALSE
C4=9: FALSE
C5=1: FALSE
C5=2: FALSE
C5=3: FALSE
C5=4: FALSE
C5=5: FALSE
C5=6: FALSE
C5=7: FALSE
C5=8: FALSE
C5=9: FALSE
C6=1: FALSE
C6=2: FALSE
C6=3: FALSE
C6=4: FALSE
C6=5: FALSE
C6=6: FALSE
C6=7: FALSE
C6=8: FALSE
C6=9: FALSE
C7=1: FALSE
C7=2: FALSE
C7=3: FALSE
C7=4: FALSE
C7=5: FALSE
C7=6: FALSE
C7=7: FALSE
C7=8: FALSE
C7=9: FALSE
C8=1: FALSE
C8=2: FALSE
C8=3: FALSE
C8=4: FALSE
C8=5: FALSE
C8=6: FALSE
C8=7: FALSE
C8=8: FALSE
C8=9: FALSE
C9=1: FALSE
C9=2: FALSE
C9=3: FALSE
C9=4: FALSE
C9=5: FALSE
C9=6: FALSE
C9=7: FALSE
C9=8: FALSE
C9=9: FALSE
D1=1: FALSE
D1=2: FALSE
D1=3: FALSE
D1=4: FALSE
D1=5: FALSE
D1=6: FALSE
D1=7: FALSE
D1=8: FALSE
D1=9: FALSE
D2=1: FALSE
D2=2: FALSE
D2=3: FALSE
D2=4: FALSE
D2=5: FALSE
D2=6: FALSE
D2=7: FALSE
D2=8: FALSE
D2=9: FALSE
D3=1: FALSE
D3=2: FALSE
D3=3: FALSE
D3=4: FALSE
D3=5: FALSE
D3=6: FALSE
D3=7: FALSE
D3=8: FALSE
D3=9: FALSE
D4=1: FALSE
D4=2: FALSE
D4=3: FALSE
D4=4: FALSE
D4=5: FALSE
D4=6: FALSE
D4=7: FALSE
D4=8: FALSE
D4=9: FALSE
D5=1: FALSE
D5=2: FALSE
D5=3: FALSE
D5=4: FALSE
D5=5: FALSE
D5=6: FALSE
D5=7: FALSE
D5=8: FALSE
D5=9: FALSE
D6=1: FALSE
D6=2: FALSE
D6=3: FALSE
D6=4: FALSE
D6=5: FALSE
D6=6: FALSE
D6=7: FALSE
D6=8: FALSE
D6=9: FALSE
D7=1: FALSE
D7=2: FALSE
D7=3: FALSE
D7=4: FALSE
D7=5: FALSE
D7=6: FALSE
D7=7: FALSE
D7=8: FALSE
D7=9: FALSE
D8=1: FALSE
D8=2: FALSE
D8=3: FALSE
D8=4: FALSE
D8=5: FALSE
D8=6: FALSE
D8=7: FALSE
D8=8: FALSE
D8=9: FALSE
D9=1: FALSE
D9=2: FALSE
D9=3: FALSE
D9=4: FALSE
D9=5: FALSE
D9=6: FALSE
D9=7: FALSE
D9=8: FALSE
D9=9: FALSE
E1=1: FALSE
E1=2: FALSE
E1=3: FALSE
E1=4: FALSE
E1=5: FALSE
E1=6: FALSE
E1=7: FALSE
E1=8: FALSE
E1=9: FALSE
E2=1: FALSE
E2=2: FALSE
E2=3: FALSE
E2=4: FALSE
E2=5: FALSE
E2=6: FALSE
E2=7: FALSE
E2=8: FALSE
E2=9: FALSE
E3=1: FALSE
E3=2: FALSE
E3=3: FALSE
E3=4: FALSE
E3=5: FALSE
E3=6: FALSE
E3=7: FALSE
E3=8: FALSE
E3=9: FALSE
E4=1: FALSE
E4=2: FALSE
E4=3: FALSE
E4=4: FALSE
E4=5: FALSE
E4=6: FALSE
E4=7: FALSE
E4=8: FALSE
E4=9: FALSE
E5=1: FALSE
E5=2: FALSE
E5=3: FALSE
E5=4: FALSE
E5=5: FALSE
E5=6: FALSE
E5=7: FALSE
E5=8: FALSE
E5=9: FALSE
E6=1: FALSE
E6=2: FALSE
E6=3: FALSE
E6=4: FALSE
E6=5: FALSE
E6=6: FALSE
E6=7: FALSE
E6=8: FALSE
E6=9: FALSE
E7=1: FALSE
E7=2: FALSE
E7=3: FALSE
E7=4: FALSE
E7=5: FALSE
E7=6: FALSE
E7=7: FALSE
E7=8: FALSE
E7=9: FALSE
E8=1: FALSE
E8=2: FALSE
E8=3: FALSE
E8=4: FALSE
E8=5: FALSE
E8=6: FALSE
E8=7: FALSE
E8=8: FALSE
E8=9: FALSE
E9=1: FALSE
E9=2: FALSE
E9=3: FALSE
E9=4: FALSE
E9=5: FALSE
E9=6: FALSE
E9=7: FALSE
E9=8: FALSE
E9=9: FALSE
F1=1: FALSE
F1=2: FALSE
F1=3: FALSE
F1=4: FALSE
F1=5: FALSE
F1=6: FALSE
F1=7: FALSE
F1=8: FALSE
F1=9: FALSE
F2=1: FALSE
F2=2: FALSE
F2=3: FALSE
F2=4: FALSE
F2=5: FALSE
F2=6: FALSE
F2=7: FALSE
F2=8: FALSE
F2=9: FALSE
F3=1: FALSE
F3=2: FALSE
F3=3: FALSE
F3=4: FALSE
F3=5: FALSE
F3=6: FALSE
F3=7: FALSE
F3=8: FALSE
F3=9: FALSE
F4=1: FALSE
F4=2: FALSE
F4=3: FALSE
F4=4: FALSE
F4=5: FALSE
F4=6: FALSE
F4=7: FALSE
F4=8: FALSE
F4=9: FALSE
F5=1: FALSE
F5=2: FALSE
F5=3: FALSE
F5=4: FALSE
F5=5: FALSE
F5=6: FALSE
F5=7: FALSE
F5=8: FALSE
F5=9: FALSE
F6=1: FALSE
F6=2: FALSE
F6=3: FALSE
F6=4: FALSE
F6=5: FALSE
F6=6: FALSE
F6=7: FALSE
F6=8: FALSE
F6=9: FALSE
F7=1: FALSE
F7=2: FALSE
F7=3: FALSE
F7=4: FALSE
F7=5: FALSE
F7=6: FALSE
F7=7: FALSE
F7=8: FALSE
F7=9: FALSE
F8=1: FALSE
F8=2: FALSE
F8=3: FALSE
F8=4: FALSE
F8=5: FALSE
F8=6: FALSE
F8=7: FALSE
F8=8: FALSE
F8=9: FALSE
F9=1: FALSE
F9=2: FALSE
F9=3: FALSE
F9=4: FALSE
F9=5: FALSE
F9=6: FALSE
F9=7: FALSE
F9=8: FALSE
F9=9: FALSE
G1=1: FALSE
G1=2: FALSE
G1=3: FALSE
G1=4: FALSE
G1=5: FALSE
G1=6: FALSE
G1=7: FALSE
G1=8: FALSE
G1=9: FALSE
G2=1: FALSE
G2=2: FALSE
G2=3: FALSE
G2=4: FALSE
G2=5: FALSE
G2=6: FALSE
G2=7: FALSE
G2=8: FALSE
G2=9: FALSE
G3=1: FALSE
G3=2: FALSE
G3=3: FALSE
G3=4: FALSE
G3=5: FALSE
G3=6: FALSE
G3=7: FALSE
G3=8: FALSE
G3=9: FALSE
G4=1: FALSE
G4=2: FALSE
G4=3: FALSE
G4=4: FALSE
G4=5: FALSE
G4=6: FALSE
G4=7: FALSE
G4=8: FALSE
G4=9: FALSE
G5=1: FALSE
G5=2: FALSE
G5=3: FALSE
G5=4: FALSE
G5=5: FALSE
G5=6: FALSE
G5=7: FALSE
G5=8: FALSE
G5=9: FALSE
G6=1: FALSE
G6=2: FALSE
G6=3: FALSE
G6=4: FALSE
G6=5: FALSE
G6=6: FALSE
G6=7: FALSE
G6=8: FALSE
G6=9: FALSE
G7=1: FALSE
G7=2: FALSE
G7=3: FALSE
G7=4: FALSE
G7=5: FALSE
G7=6: FALSE
G7=7: FALSE
G7=8: FALSE
G7=9: FALSE
G8=1: FALSE
G8=2: FALSE
G8=3: FALSE
G8=4: FALSE
G8=5: FALSE
G8=6: FALSE
G8=7: FALSE
G8=8: FALSE
G8=9: FALSE
G9=1: FALSE
G9=2: FALSE
G9=3: FALSE
G9=4: FALSE
G9=5: FALSE
G9=6: FALSE
G9=7: FALSE
G9=8: FALSE
G9=9: FALSE
H1=1: FALSE
H1=2: FALSE
H1=3: FALSE
H1=4: FALSE
H1=5: FALSE
H1=6: FALSE
H1=7: FALSE
H1=8: FALSE
H1=9: FALSE
H2=1: FALSE
H2=2: FALSE
H2=3: FALSE
H2=4: FALSE
H2=5: FALSE
H2=6: FALSE
H2=7: FALSE
H2=8: FALSE
H2=9: FALSE
H3=1: FALSE
H3=2: FALSE
H3=3: FALSE
H3=4: FALSE
H3=5: FALSE
H3=6: FALSE
H3=7: FALSE
H3=8: FALSE
H3=9: FALSE
H4=1: FALSE
H4=2: FALSE
H4=3: FALSE
H4=4: FALSE
H4=5: FALSE
H4=6: FALSE
H4=7: FALSE
H4=8: FALSE
H4=9: FALSE
H5=1: FALSE
H5=2: FALSE
H5=3: FALSE
H5=4: FALSE
H5=5: FALSE
H5=6: FALSE
H5=7: FALSE
H5=8: FALSE
H5=9: FALSE
H6=1: FALSE
H6=2: FALSE
H6=3: FALSE
H6=4: FALSE
H6=5: FALSE
H6=6: FALSE
H6=7: FALSE
H6=8: FALSE
H6=9: FALSE
H7=1: FALSE
H7=2: FALSE
H7=3: FALSE
H7=4: FALSE
H7=5: FALSE
H7=6: FALSE
H7=7: FALSE
H7=8: FALSE
H7=9: FALSE
H8=1: FALSE
H8=2: FALSE
H8=3: FALSE
H8=4: FALSE
H8=5: FALSE
H8=6: FALSE
H8=7: FALSE
H8=8: FALSE
H8=9: FALSE
H9=1: FALSE
H9=2: FALSE
H9=3: FALSE
H9=4: FALSE
H9=5: FALSE
H9=6: FALSE
H9=7: FALSE
H9=8: FALSE
H9=9: FALSE
J1=1: FALSE
J1=2: FALSE
J1=3: FALSE
J1=4: FALSE
J1=5: FALSE
J1=6: FALSE
J1=7: FALSE
J1=8: FALSE
J1=9: FALSE
J2=1: FALSE
J2=2: FALSE
J2=3: FALSE
J2=4: FALSE
J2=5: FALSE
J2=6: FALSE
J2=7: FALSE
J2=8: FALSE
J2=9: FALSE
J3=1: FALSE
J3=2: FALSE
J3=3: FALSE
J3=4: FALSE
J3=5: FALSE
J3=6: FALSE
J3=7: FALSE
J3=8: FALSE
J3=9: FALSE
J4=1: FALSE
J4=2: FALSE
J4=3: FALSE
J4=4: FALSE
J4=5: FALSE
J4=6: FALSE
J4=7: FALSE
J4=8: FALSE
J4=9: FALSE
J5=1: FALSE
J5=2: FALSE
J5=3: FALSE
J5=4: FALSE
J5=5: FALSE
J5=6: FALSE
J5=7: FALSE
J5=8: FALSE
J5=9: FALSE
J6=1: FALSE
J6=2: FALSE
J6=3: FALSE
J6=4: FALSE
J6=5: FALSE
J6=6: FALSE
J6=7: FALSE
J6=8: FALSE
J6=9: FALSE
J7=1: FALSE
J7=2: FALSE
J7=3: FALSE
J7=4: FALSE
J7=5: FALSE
J7=6: FALSE
J7=7: FALSE
J7=8: FALSE
J7=9: FALSE
J8=1: FALSE
J8=2: FALSE
J8=3: FALSE
J8=4: FALSE
J8=5: FALSE
J8=6: FALSE
J8=7: FALSE
J8=8: FALSE
J8=9: FALSE
J9=1: FALSE
J9=2: FALSE
J9=3: FALSE
J9=4: FALSE
J9=5: FALSE
J9=6: FALSE
J9=7: FALSE
J9=8: FALSE
J9=9: FALSE