Logic Masters Deutschland e.V.

It was about time I set another Summation U-Bahn as it very well might be one of my favourite rulesets to set with. I hope you enjoy!

Rules

• Draw a loop network through the centers of some cells, which may branch or turn, but may not have any dead ends.


• Assign each line shape (irrespective of rotation) a digit from 1 to 4 as follows: corner = 1, straight line = 2, branch = 3, cross = 4.


• Summation U-Bahn clues indicate the sum of "digits" in each contiguous sequence of cells visited by the loop network, in the correct order. Consecutive sequences must be separated by at least one cell not visited by the loop network.


• Skyscrapers clues count the number of line shapes seen from that direction, where each "digit" blocks the view of smaller or equal digits.


• Clues to the right and bottom of the grid are Skyscrapers clues. On the left and top side the Skyscrapers clues are mixed in with Summation U-Bahn clues. If there are both Summation U-Bahn and Skyscrapers clues in a row of column, the Skyscrapers clue can appear anywhere. If there is a single clue in a row or column, it can be either Summation U-Bahn or Skyscrapers.


• Each letter represents a different number. A "?" may represent any number, including two-digit numbers.

Puzzle links

SudokuPad
Penpa+