One of the nice things about this variant is that there are software solvers that support it - Ruud's "SumoCue" and Richard Broughton's "Sudoku Solver" (SS).

Ruud created a one-line format, and the SS program supports this format, so you can paste the puzzle definitions directly into SS, which has a suite of Sudoku solving techniques, and some that are particular to Jigsaws and Killers (eg "Law of Leftovers", "Law of 45", "Split Cages").

SS has a scoring (rating) system, and this puzzle gets a rating of 0.95, which puts it in the "medium" difficulty class.

The "SumoCue" definition string for the puzzle above is:

SumoCueV1=17J1+0J1=19J1+2J2=14J2+4J2=27J2+6J2=20J3=16J1+0J1+0J1+2J2+4J2=14J2+6J2+8J3+8J3+9J1+9J1=8J1+20J4+20J4+14J4+6J3+6J3+8J3=25J5+27J5=20J5+29J5=21J4=10J3+32J3+32J3=24J6+27J5+29J5+29J5+29J5+31J4=21J6+41J6+41J6+35J6+27J5=14J7+46J7+46J7+31J4+41J6+41J6+35J6+35J6=19J7=31J7+55J7=11J4=18J4+58J4+58J8=7J8+61J8+54J7+54J7+55J9+57J9=10J9=14J9=25J8+69J8+61J8+54J7+55J9+55J9+67J9+67J9+68J9+68J8+69J8+69J8

My puzzle definitions use a simple 3-line (81 character) format:

- Solution (or cage-sum list)

- Code: Select all
`AAABBBBBCAAABBBBCCAAADDDCCCEEEEDCCCFEEEEDFFFFEGGGDFFFFGGGDDDHHHGGIIIIHHHGIIIIIHHH`

AABBCCDDEFAABCGDEEFFHHHGDDEIIJJKLLLMIJJJKNNNMIOOOKNNMMPQQRSSSTTPPQRUVWWTPQQUUVVWW

378465219561738924294316875952841367713692458427589136839257641146973582685124793

The cage layout string is just a cell-to-cage assignment list, exactly as for Jigsaw layouts. Note that all characters beyond "Z" (90) are printable up to "~" (126) so that gives us 62 cage index characters, which is more than enough.

Cage sums can be obtained from the solution string, or alternatively, the solution string can be replaced by a comma-separated list of sums.