Yajilin (Minesweeper) (884)

Blacken some white cells and then draw a single closed loop (without intersections or crossings) through all remaining white cells. Loop paths must be orthogonal. Blackened cells cannot share an edge with each other. Some cells are outlined and in gray and cannot be part of the loop.
Numbers in grey cells indicate the total number of blackened cells adjacent to that cell (including diagonally adjacent cells).

Reference: WPF (1)