The full logical solve of the hard Heyawake for September 22 to September 28, 2026, 10 × 10. 73 steps, 6 techniques, no guessing. Step through it, or jump to any step below.
A 0 room has no shaded cells, so every cell in it is white.
Try every way to fit 2 shaded cells into the open cells of the 2 room without breaking a rule. Only one way works, and it settles r4c2, r5c2 and r6c2.
Shaded cells never touch by an edge, so the open cells beside r4c2 are white.
Shaded cells never touch by an edge, so the open cells beside r6c2 are white.
Suppose r3c1 is shaded. Following rules 1 to 4 from there, the white cells would split apart. So it is white.
Suppose r8c2 is white. Following rules 1 to 4 from there, the white cells would split apart. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r8c2 are white.
Suppose r4c4 is shaded. Following rules 1 to 4 from there, the white cells would split apart. So it is white.
Suppose r6c4 is shaded. Following rules 1 to 4 from there, the white cells would split apart. So it is white.
If r6c5 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r6c5 are white.
This room needs one more shaded cell and has exactly one open cell, so it is shaded.
Shaded cells never touch by an edge, so the open cells beside r8c5 are white.
Try every way to fit 2 shaded cells into the open cells of the 3 room without breaking a rule. Only one way works, and it settles r4c5, r4c6 and r5c6.
Shaded cells never touch by an edge, so the open cells beside r4c5 are white.
Shaded cells never touch by an edge, so the open cells beside r5c6 are white.
Shading r5c4 would cut the white cells into two groups. White cells must all connect, so it is white.
If r5c3 were white, a white line would run from one room through the next into a third. So it is shaded.
If r3c4 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r3c4 are white.
If r7c4 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r7c4 are white.
If r7c1 were white, a white line would run from one room through the next into a third. So it is shaded.
Shading r5c1 would cut the white cells into two groups. White cells must all connect, so it is white.
Shading r7c6 would cut the white cells into two groups. White cells must all connect, so it is white.
If r7c7 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r7c7 are white.
If r8c8 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r8c8 are white.
Suppose r6c8 is shaded. Following rules 1 to 4 from there, the white cells would split apart. So it is white.
If r6c9 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r6c9 are white.
Suppose r9c3 is shaded. Following rules 1 to 4 from there, the white cells would split apart. So it is white.
If r9c4 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r9c4 are white.
Suppose r2c3 is white. Following rules 1 to 4 from there, the white cells would split apart. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r2c3 are white.
Suppose r1c2 is shaded. Following rules 1 to 4 from there, the white cells would split apart. So it is white.
This room needs one more shaded cell and has exactly one open cell, so it is shaded.
Shaded cells never touch by an edge, so the open cells beside r1c1 are white.
Suppose r1c4 is shaded. Following rules 1 to 4 from there, the white cells would split apart. So it is white.
Suppose r2c5 is shaded. Following rules 1 to 4 from there, the white cells would split apart. So it is white.
Suppose r9c6 is shaded. Following rules 1 to 4 from there, the white cells would split apart. So it is white.
If r9c7 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r9c7 are white.
If r10c6 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r10c6 are white.
If r10c3 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r10c3 are white.
Shading r10c8 would cut the white cells into two groups. White cells must all connect, so it is white.
If r10c9 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r10c9 are white.
Shading r9c10 would cut the white cells into two groups. White cells must all connect, so it is white.
Suppose r3c6 is shaded. Following rules 1 to 4 from there, the white cells would split apart. So it is white.
Suppose r1c5 is shaded. Following rules 1 to 4 from there, two shaded cells would touch. So it is white.
If r1c6 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r1c6 are white.
This room already has its one shaded cell, so its other cells are white.
If r2c7 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r2c7 are white.
This room needs one more shaded cell and has exactly one open cell, so it is shaded.
Shaded cells never touch by an edge, so the open cells beside r3c8 are white.
Shading r4c7 would cut the white cells into two groups. White cells must all connect, so it is white.
If r4c9 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r4c9 are white.
Shading r3c10 would cut the white cells into two groups. White cells must all connect, so it is white.
Shading r5c10 would cut the white cells into two groups. White cells must all connect, so it is white.
If r5c8 were white, a white line would run from one room through the next into a third. So it is shaded.
If r2c10 were white, a white line would run from one room through the next into a third. So it is shaded.
Shaded cells never touch by an edge, so the open cells beside r2c10 are white.
Shading r1c9 would cut the white cells into two groups. White cells must all connect, so it is white.
Shading r7c10 would cut the white cells into two groups. White cells must all connect, so it is white.
If r8c10 were white, a white line would run from one room through the next into a third. So it is shaded.