Place the nine half dominoes into the grid, without rotating or reflecting them. Numbers indicate how many dots are there in the given row, column or diagonal.
(Rules and example from WPC 2011 IB)
History of the puzzle
Appeared on WPC 1999/Part 5, an "innovative" round. The author of the puzzle is unknown.
Appearances in the past WPCs
- WPC 2018/Round 4 (Triangular) by Jiří Hrdina