Easy as ABC (Transparent) by Prasanna Seshadri
or solve online (using our beta test of Penpa-Edit tools; use tab to alternate between a letter entry mode and a shading mode. CAPS LOCK is recommended for letter entry.)
Theme: Yell Out Greetings!
Author/Opus: This is the 245th puzzle from our contributing puzzlemaster Prasanna Seshadri.
Rules: Fill some empty cells with the letters E, H, I, L, O, Y (A, B, C, D in the example) so that each row and column contains each letter exactly once. The letters outside the grid indicate the first letter seen from that direction, but each row and column has one transparent letter that is ignored by the clues. The transparent letters must be different in each row and column.
See also this example:
Difficulty: 3.5 stars
Time Standards (highlight to view): Grandmaster = 3:45, Master = 8:30, Expert = 17:00
Solution: PDF and solving video.
Note: Follow this link for other less common Number Placement variations.
It’s not immediately clear from the instructions that “The transparent letters must be different in each row and column” is a statement about both the positions of the transparent letters *and* the fact that each letter is transparent only once. The example did help deduce the second reading.
This is why we also provide the visual example, as the English is written precisely but in some instructions may not capture full meaning for every reader.
Indeed in these puzzles, “the transparent letters must be different” across the puzzle and in a sudoku sense, form another complete set of letters without repeats.