Hidden Necklace
- Shading
- Whisper lines
- Odd and even cells
The brief
Normal sudoku rules apply.
Cells marked with grey circles contain odd digits. Cells marked with grey squares contain even digits.
Shade some cells such that the resulting pattern is 90-degree rotationally symmetric. For example, if r1c4 is shaded, then so are r4c9, r9c6, and r6c1.
The unshaded region must contain one each of the twelve standard pentominoes (no repeats by rotation or reflection).
Each pentomino encloses exactly one grey square, one grey circle, and one caged cell.
The arrangement of pentominoes must be deduced.
A single green line loops through all twelve pentominoes (some of it is shown). It passes through exactly 2 cells of a pentomino before visiting the next. The line does not enter any cell containing a cage or a grey circle. Adjacent digits along the green line differ by at least 5.
Each pentomino behaves like a 5-cell killer cage: digits do not repeat and must sum to the value shown in the corner of the caged cell (if given).
Illustrated Pentominoes at: https://tinyurl.com/pent-labels