Logic Masters Deutschland e.V.

This puzzle has been constructed for the 24 hour puzzle championship this year. It has been too difficult and hence replaced by another puzzle with the same rules. The unused puzzle now is reused as a training puzzle.

Regeln: Draw an Underground network (by Underground rules) and put some magnets in the grid (by Magnets rules) such that the Underground network does not go through magnets. Clue numbers for "T"-shaped crossings and turns count the cells with the corresponding Underground type. "X"-shaped crossings and straight line clues indicate the sum of the corresponding Underground clue and the corresponding Magnets clue. It is possible for dominoes to stay completely empty or be only half filled by the Undergrond network.

Underground rules: Draw orthogonal connections through centers of cells to form one connected network. It is not allowed to have any cell with only one connection. It is allowed for any cell to have no connections. Each cell with connections will therefore be one of these four types: A turn, a straight line, a "T"-shaped crossing or an "X"-shaped crossing. The numbers above and to the left of the grid indicate the exact number of cells of the specified type that must be placed in each column or row, respectively. If a number is not given, there might be any number of cells of the specified type.

Magnets rules: Locate some magnets in the grid. A magnet is two square cells that touch along an edge; one cell must be marked with only a "positive" (+) symbol and the other cell must be marked with only a "negative" (–) symbol.Cells that share an edge cannot contain the same symbol.The grid is divided into regions; each region has an area of 2 cells. Each region either fully contains a magnet or is left empty.The numbers above and to the left of the grid indicate the exact number of symbols of the specified type that must be placed in each column or row, respectively. If a number is not given, there might be any number of symbols of the specified type.