Board classification LinkedIn Queens #794. Dimensions 9×9. Region sample count 9. Observed pattern: tight-region board. Placement vector: R1C2, R2C8, R3C3, R4C7, R5C4, R6C1, R7C5, R8C9, R9C6.
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 2 to 18 cells — smaller regions often pin a queen to a single row intersection.
Sample placement 1: R1C2. Constraint class: elimination. Row 1, column 2 is the forced queen once region 2, row, column, and touch rules are applied together.
Sample placement 2: R2C8. Constraint class: elimination. Row 2, column 8 is the forced queen once region 3, row, column, and touch rules are applied together.
Sample placement 3: R3C3. Constraint class: elimination. Row 3, column 3 is the forced queen once region 4, row, column, and touch rules are applied together.
Sample placement 4: R4C7. Constraint class: elimination. Row 4, column 7 is the forced queen once region 5, row, column, and touch rules are applied together.
Sample placement 5: R5C4. Constraint class: elimination. Row 5, column 4 is the forced queen once region 6, row, column, and touch rules are applied together.
Sample placement 6: R6C1. Constraint class: rowScan. After eliminations, row 6 has one legal square left — column 1.
Sample placement 7: R7C5. Constraint class: regionPin. Region 7 only touches row 7 once on this board, so its queen must land at column 5.
Sample placement 8: R8C9. Constraint class: rowScan. After eliminations, row 8 has one legal square left — column 9.
Sample placement 9: R9C6. Constraint class: rowScan. After eliminations, row 9 has one legal square left — column 6.
Lab result: Tight-region board. Coordinates R1C2, R2C8, R3C3, R4C7, R5C4, R6C1, R7C5, R8C9, R9C6.