Logic Masters Deutschland e.V.

Rank Up: a series by ThePedallingPianist and bellal exploring the full rank constraint within 5x5 grids... SEE ALL PUZZLES

This series has slowed somewhat as my dad and I have approached our intended final instalment, #20, as we've been anxiously trying to make sure we cover the best possible variants to combine with full rank in the few slots that remain. After all the permacultures I had to solve as a judge for damasosos92's fantastic setting competition, this seemed like apt revenge on the community.

Whilst I am the primary culprit for setting this one, I must thank my dad enormously for his help with programming to find that such a grid was possible.



Concise Rule Description:
• Full Rank 5x5 Sudoku;
• Some of the grid contains a Masyu loop that acts as a Modular Line;
• The rest of the grid contains a Snake and Eggs whose sizes (1-5) appear as a value somewhere in the Egg, sometimes circled.

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Permaculture: Divide the grid into two regions. One region adheres to Masyu (Full) rules, and the other adheres to Snake Egg rules.

Masyu (Full): Draw a non-intersecting loop through the centers of all cells. The loop must go straight through white circles, and turn in at least one of the cells on either side. In addition, the loop forms a valid Modular Line, i.e. every three sequential values along the loop must contain a complete set of residues modulo 3.

Snake Egg: Shade some cells to form a non-intersecting "Snake" which does not branch or touch itself orthogonally. Circles mark the ends of the Snake. Exactly one orthogonally connected area of unshaded cells, an "Egg", must exist of each size from 1 to 5. The size of an Egg in number of cells must appear as a value in at least one of its cells, which may be marked by a white circle.

[White Circle Clarification: A white circle may either clue (1) a straight section of the Masyu loop; (2) one of the ends of the Snake, or (3) a cell belonging to an Egg that contains a value equal to that Egg's size.]

Sudoku: Within the main grid (inside the thick border), fill every cell with a digit from 1-5 such that digits do not repeat in a row or column.

Full Rank: A value in an external cell represents the rank of the number formed by reading the digits in that row or column from that direction, where (1) is the lowest such row or column and (20) is the highest.

N.B. If two ranks are tied, the value in both external cells is the lower of the two ranks being shared. For example, if the lowest four ranks are "1", "32", "32" and "51", the values in the relevant external cells would be (1), (2), (2) and (4) respectively.