Regional Yajilin
Regional Yajilin was originally invented by Naoki Inaba (Japan) in 2005 under the name ブロックボックス (Block Box). The variant was later independently reinvented by Prasanna Seshadri (India) in 2012, who gave it the name Regional Yajilin. This title became widely recognized following the “Borders & Beyond” contest on Logic Masters India, where the puzzle gained popularity among solvers.
Unlike traditional Yajilin puzzles, Regional Yajilin does not use directional arrows—the Yaji element of the original name—but instead divides the grid into regions that determine the placement of shaded cells and the loop. This structural change introduces a distinct form of logical reasoning while preserving the elegant path-drawing character that links it to the Yajilin family.
Unlike traditional Yajilin puzzles, Regional Yajilin does not use directional arrows—the Yaji element of the original name—but instead divides the grid into regions that determine the placement of shaded cells and the loop. This structural change introduces a distinct form of logical reasoning while preserving the elegant path-drawing character that links it to the Yajilin family.
Rules
Shade some cells black and then draw a single non-intersecting loop through all white cells. Black cells cannot share an edge with each other. Numbers indicate the number of cells shaded black in the corresponding area.
Click to see the answer.