Slash Pack: 250 Medium to Hard 9x9 Logic Puzzles with Answers

Slash Pack is a logic puzzle invented by Yosuke Imai (Japan). The grid of irregular shape contains numbers from 1 to N in some cells. The goal is to divide the grid into regions by placing the diagonal lines into empty cells. Each region must contain the numbers from 1 to N exactly once. Two diagonals cannot cross in one cell, and there can be no loose ends.