Logic Masters Deutschland e.V.

Sudoku in Sudoku — Hard Version

(Eingestellt am 3. Januar 2026, 13:23 Uhr von Kutsumi Hane)

Rules:

Normal Sudoku rules apply, requiring that each row, column, and 3×3 box contains the digits 1-9 exactly once. Additionally:
    ·Disjoint Groups:
    Cells with the same position within the boxes contain all the numbers 1-9.
    ·Little Killers:
    Digits along marked diagonals sum to the number indicated outside the grid.
    ·Sub-Sudoku:
    Diamond cells form a 5×5 Irregular Sudoku with its irregular regions colored differently.
    ·Magic Square:
    Box 5 is a Magic Square, i.e. every row, column and 3-cell diagonal within the box sums to 15.
    ·Quadruples/Doubles:
    All digits inside a circle appear in at least one of the four/two surrounding cells.

Here you can solve the puzzle online: Solve on SudokuPad
The difficulty is probably 4-5 stars. I wish you joyful solving! (See also Easy Version)

Hint:

· The solve involves symbolic reasoning with letter variables rather than direct numeric deduction.
·
 
All 3×3 Magic Squares form a single orbit under the Dihedral Group (D4).
Check whether the Magic Squares formed by the numbers in Quadruples/Doubles and Box 5 are equivalent under rotations of D4.

Lösungscode: Digits in the center of each box, listed from Box 1 to Box 9.

Zuletzt geändert am 4. Januar 2026, 17:07 Uhr

Gelöst von lmdemasi, jordanza, SKORP17, HeyItsErin, amaoto, pms_headache, han233ing, War
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Kommentare

Zuletzt geändert am 4. Januar 2026, 05:09 Uhr

am 3. Januar 2026, 16:49 Uhr von Rollo
I can't see any difference between this and the easy version.
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Response from Kutsumi Hane:
Thanks for your comment and for taking the time to compare the two versions - much appreciated, and happy solving. You are right that both versions lead to the same final solution. However, the Hard version removes one given constraint - the "No Triple Evens" rule.
In the Easy version, this rule allows certain branches in the solving path to be ruled out very quickly, because sequences of three even digits can be eliminated immediately. In the Hard version, without that constraint, these branches are no longer pruned automatically; the solver must carry the reasoning further — unless one proceeds by brute-force trial-and-error guessing. This makes the logical path less direct and therefore increases the difficulty.
So the puzzle content and final solution are identical, but the intended solving experience is different.

am 3. Januar 2026, 15:03 Uhr von Kutsumi Hane
Modified the Solution Code requirements;
Difficulty adjusted to 4 stars.

Schwierigkeit:5
Bewertung:N/A
Gelöst:8 mal
Beobachtet:0 mal
ID:000QU9

Rätselvariante Variantenkombination Mathematikkenntnisse Unregelmäßiges Gitter Arithmetikrätsel Lateinisches Quadrat

Lösung abgeben

Lösungscode:

Anmelden