Board classification LinkedIn Queens #819. Dimensions 8×8. Region sample count 8. Observed pattern: tight-region board. Placement vector: R1C1, R2C3, R3C6, R4C4, R5C7, R6C5, R7C8, R8C2.
Board spotlight: Several color regions span only a few cells — scan those regions first because they often force a queen into a single row or column. Region sizes range from 1 to 14 cells — smaller regions often pin a queen to a single row intersection.
Sample placement 1: R1C1. Constraint class: regionPin. Region 1 only touches row 1 once on this board, so its queen must land at column 1.
Sample placement 2: R2C3. Constraint class: regionPin. Region 3 only touches row 2 once on this board, so its queen must land at column 3.
Sample placement 3: R3C6. Constraint class: elimination. Row 3, column 6 is the forced queen once region 5, row, column, and touch rules are applied together.
Sample placement 4: R4C4. Constraint class: elimination. Row 4, column 4 is the forced queen once region 4, row, column, and touch rules are applied together.
Sample placement 5: R5C7. Constraint class: elimination. Row 5, column 7 is the forced queen once region 7, row, column, and touch rules are applied together.
Sample placement 6: R6C5. Constraint class: rowScan. After eliminations, row 6 has one legal square left — column 5.
Sample placement 7: R7C8. Constraint class: regionPin. Region 8 only touches row 7 once on this board, so its queen must land at column 8.
Sample placement 8: R8C2. Constraint class: rowScan. After eliminations, row 8 has one legal square left — column 2.
Lab result: Tight-region board. Coordinates R1C1, R2C3, R3C6, R4C4, R5C7, R6C5, R7C8, R8C2.