Binairo

Medium Binairo uses an 8×8 grid, increasing the cells to 64 and the target count to four 0s and four 1s per row and column. The larger grid means consecutive forcing alone is not always enough — you need to combine it with counting and sandwich patterns.

Watch for sandwich patterns: if cells A and C both hold 0 with an empty cell B between them (0-?-0), cell B must be 1. When a row has three of one digit and several empty cells, use the count constraint to eliminate candidates and look for forced placements.

Ready for larger grids? Try hard.