Logic Masters Deutschland e.V.

Standard sudoku rules applies. Fill the grid with numbers from 1 to 9 so each digit occurs exactly once in every row, column and 3x3 box.

Clue outside is also the x-th digit in that direction, where x is the first digit the clue sees. All clues are given.

Every line is a palindrome. Digits on the line read the same from both side.

This puzzle probably is the first puzzle that is interesting enough that Old Miles solved it. My style slowly take into shape, mainly by stacking structures.

About this puzzle, i try to find what could i like from two of my most hated variant. For room number, the problem is clues are generic and kind of useless. Compared with skyscraper who has 19 as iconic outside clues, room number just don’t have any clues that looks interesting,maybe a row of certain digit or 1 to 9. For palindrome, the problem is hard to identify which cell equal to which, plus not empty grid.

The interesting thing is, when combined, i only need to deal with the palindrome problem and the room number part is solved on the way. For me, it proved room number is so boring that even its problem is superficial. Even now, i still can’t answer what makes room number interesting. It is probably still the most unnoticed variant in the outside clue variant.