Brain Teasers for Adults: Triplets Puzzles - 100 Large Puzzles for Adults

Triplets ("One or All") is a logic puzzle invented by Naoki Inaba (Japan). The task consists of a rectangular or square grid divided into regions of exactly three cells. Some cells contain figures of 3 kinds: squares, circles, triangles. The goal is to fill in each cell with figures. Each region must contain all identical or all different figures. When two figures are orthogonally adjacent across a region boundary, the figures must be different.