Case LinkedIn Queens #822: 9×9 grid, 9 colored regions. Nine exhibits — queen coordinates R1C6, R2C9, R3C5, R4C7, R5C1, R6C3, R7C8, R8C4, R9C2. No two queens may share row, column, region, or adjacency.
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 3 to 18 cells — smaller regions often pin a queen to a single row intersection.
Exhibit 1: queen at R1C6. Row 1, column 6 is the forced queen once region 1, row, column, and touch rules are applied together.
Exhibit 2: queen at R2C9. Row 2, column 9 is the forced queen once region 4, row, column, and touch rules are applied together.
Exhibit 3: queen at R3C5. Row 3, column 5 is the forced queen once region 3, row, column, and touch rules are applied together.
Exhibit 4: queen at R4C7. After eliminations, row 4 has one legal square left — column 7.
Exhibit 5: queen at R5C1. Row 5, column 1 is the forced queen once region 5, row, column, and touch rules are applied together.
Exhibit 6: queen at R6C3. Region 6 only touches row 6 once on this board, so its queen must land at column 3.
Exhibit 7: queen at R7C8. After eliminations, row 7 has one legal square left — column 8.
Exhibit 8: queen at R8C4. Region 7 only touches row 8 once on this board, so its queen must land at column 4.
Exhibit 9: queen at R9C2. After eliminations, row 9 has one legal square left — column 2.
Verdict: placement set R1C6, R2C9, R3C5, R4C7, R5C1, R6C3, R7C8, R8C4, R9C2 is consistent with every rule. Case closed.