Logic Masters Deutschland e.V.

Constantinople

This is the A-Side of a pair of puzzles, introducing 'nesting clues'. I hope you enjoy them!

A-Side: Constantinople (U-Bahn with Nesting Clues).
B-Side: coming soon!

• U-Bahn: Draw some vertical and horizontal line segments between the centers of cells so that the resulting network is connected and has no dead ends. Clues outside the grid indicate how many turns, straights, branches and crosses occur in the corresponding row or column, independent of rotation.
• Nesting clues: Numbers on vertices in the grid indicate the minimum number of times a path from the clue to the grid border must cross the U-Bahn network. Paths are considered to travel orthogonally and diagonally between vertices of the grid. For example, a clue of "2" indicates that there is a path from the clue to the grid border which crosses the network twice, but there is no path crossing it fewer than twice.

These images show some valid nesting clues. Intuitively, nesting clues count "how nested" the clue is within the network. The left side shows a loop network compatible with the given nesting clues, and the right side demonstrates why the nesting clues are satisfied.

The solver is recommended to keep track of nesting values of non-clued vertices (as shown in the right image), although they are not required for the solution.