The New Sudoku Players' Forum

[urhegyi]

Tried to generate some, but hard to generate and not very high rated.

Code: Select all

2.8...4.....51...7..............86...7.4....5.1.....2.6....2.......3..1.4........ ED=6.6/1.5/1.5
8.2...4.....71...9..............46...7.2....5.1.....2.6....2.......3..1.4........ ED=6.6/1.2/1.2
2.8...6.....71...3..............82...7.6....5.1.....3.6....2.......3..1.4........ ED=6.6/1.5/1.5
8.4...6.....71...3..............82...7.6....5.1.....3.6....2.......3..1.2........ ED=6.6/1.2/1.2
2.8...4.....71...3..............82...7.4....5.1.....9.6....2.......3..1.4........ ED=6.6/1.5/1.5


[m_b_metcalf]

Tried to generate some, but hard to generate and not very high rated.

Here's a selection from a file I have, origin unknown.

Code: Select all

.......1......2.34..5.6.......7...8...2...6...4...1.......2.9..71.8......6.......   ED=1.5/1.2/1.2   
..............1.23..4.5.......6...4...3.1.5...7...2.......4.6..82.7......1.......   ED=1.7/1.2/1.2   
.......1......2.34..2.5.......3...6...7...8...5...4.......7.5..83.6......4.......   ED=2.0/1.2/1.2   
.......1......2.34..5.6.......3...5...2...6...1...7.......8.2..49.5......3.......   ED=2.3/1.2/1.2   
.......1......2.34..5.6.......7...5...2...6...4...3.......5.1..13.8......9.......   ED=2.6/1.2/1.2     
.1......23....4.......5.6.....7...5...6...1...4...3.....5.8.......6....47......3.   ED=3.4/3.4/3.4  little diamond
.......1......2.34..2.5.......3...2...6...7...5...8.......6.5..34.1......7.......   ED=3.6/1.2/1.2   
.......1......2.34..5.6.......3...2...7...8...4...1.......5.6..23.9......1.......   ED=4.2/1.2/1.2   
.1......23....4.......5.6.....1...3...5.7.8.......6.....6.8.......2....98......1.   ED=5.6/1.2/1.2   
.......1......2.34..5.6.......7.......8.2.5...3...1.......8.2..71.5......9.......   ED=6.6/1.2/1.2   
.......1......2.34..2.5.......3...6...7...8...5...4.......7.5..83.9......4.......   ED=6.7/1.2/1.2   
.......1......2.34..5.6.......3...7...2...6...1...8.......9.2..47.5......3.......   ED=7.0/1.2/1.2     
.1......23....4.......5.6.........5...4.7.8...2...3.....5.2.......1....38......9.   ED=7.1/7.1/3.4  pearl     
.1......23....4.......2.5.........6...4.7.8...5...3.....9.5.......1....36......4.   ED=7.2/7.2/3.8  pearl
.1......23....4.......5.6.......1.7...8...5...6.2.......5.3.......6....79......1.   ED=7.3/7.2/3.8   
.1......23....4.......5.6.......3.7...6...4...2.8.......4.6.......5....87......3.   ED=8.3/3.8/3.4   
.1......23....4.......5.6.......1.3...2...4...7.6.......8.6.......2....74......9.   ED=8.4/1.2/1.2   


You might find some more here and here.

Mike

[JPF]

Hi urhegyi!

If you want to quickly generate new 18-puzzles, you can use gsf's program (say sudokugsf).
Assuming your puzzles are in the file A.txt, you will get over 15,700 new 18-puzzles in just a few minutes in B.txt. The command is as follows:
sudokugsf -go{-1+1}x4 A.txt >B.txt

JPF

[eleven]

yes, neigbourhood search is the "quick" way to find low clue, high clue or hardest puzzles, i.e. remove two clues from a valid puzzle, add another one to find valid puzzles with less clues, or -1 +1 for puzzles with the same number of clues.
Somewhat counter-intuitive is the fact, that on average minimal puzzles with less clues are easier, so you will have to find a lot of 17- or 18-clue puzzles to get a hard one (with ER > 9).

[coloin]

so you will have to find a lot of 17- or 18-clue puzzles to get a hard one (with ER > 9).

you will have to find an awful lot to get one with ER>9,2 !!

I think these are the "hardest" rated 18C puzzles found to date

the-highest-rated-18-clue-puzzles