FED-SUDOKU

Ankora:I hope you can PM me to teach me if you are free.
I have solve the puzzle but why it didnot display hotovo?

lono: You don´t need a quess ;-) But you can if you want. I can´t help you here in guestbook, but if you want I can send you a message by PM on sudoku-league.com or mtronic, his english is beter than my.

Ankora,Mtronic:Thanks for your information.
I have try the puzzle yesterday and I think I have to guess to solve the puzzle.

mtronic: Yes ;-)

Ankora: Yes, I'm sorry, I did not see them, as they are not in bulleted list as in the other languages.... better to have them twice than not at all ;-)

mtronic, lono: And there are english instructions online too. ;-)

mtronic: There are instructions in the page "Dvojice" ;-)

Don't know if it is in the online help, but the pair property is not described.... so here you are:
Each of the pair is diagonally placed, one cell of the pair is white, the other is yellow and the distance (counting in rows or columns) between the cells equals the value of the pair.
The picture on the page shows correctly formed pairs.

lono: There is a new variant "Dvojice" in varinty online, you have an english version there too. Good luck. ;-)

lono: yes it's correct position for 8, but I wonder how did you get it there..... well obviously there are more ways of how to crack the table, you just followed another path. My next decisions were related to 1s, so in next early stage I had all 1s and 9s placed and 5 in block #1 and 8 in block#2 (check the 26/4 and < signs :-)

mtronic:Thanks for the hints.It is really helpful But I dont have much time to solve it.I think I have to wait until tomorrow to solve it.
Beside that,I found 8's at 78 and 84,am I right?

lono: sorry, typo.... correction for the start. In block#1 the places are 11,21,31 and 33 (row,column notation) of course.
Let me know if it has started you or you need more hints.

Recap 9 valid places 11,21,31,33, 26,35, 17,37, 42,62, 54 (already placed), 48,68, 71,81,91,83,93, 76,95,96, 79,89,99. Now will continue step what if I put 9 at XY (well did not find more logical step, but this kind is quite offten in GTK).
So quite interesting position is 33. So if 33 was 9, we have other places known... 26, 17, 95, 71/81. We can stop now, as this breaks the rule of the diagonal (both 37 and 91 were invalidated), so 33 MAY NOT contain 9! This means, that 71,81,91 are no longer valid for 9, thus we place 9 at 37 (diagonal), thus at 26, 11, 95, 83, 79. Now 7 of 9 9s placed, the rest allowed in 42/62 and 48/68. Do you follow me?

Now move your attention to block #6, there is valid position for 9 at 48 or 68 only (< constraint in column 9, the same box constraint in column 7). In the block #9 you have valid places in column 9 only (col. 7 due to less, col. 8 due to block #6). Block #3, valid places 17 and 37. Block #7 places 71,81,91,83 and 93. (Note 26/4 is either 5678 or contains 9).
Block #4 - 36/7 means all but two digits which sum is 9, so the 9 MUST be in the 36 area, and is not at 72 (less) so valid places are 42 and 62 only (no 9 in column 2 in blocks #1 and #7).

lono: ok, so lets start.
the 21(6) total in left upper corner must contain 123456. So possible places for 9 in block#1 is 11,12,13 and 33 (row,column notation). In block #2 the only place is 26 or 35 (other are < neighbor, which means no 9, 14 can be 1-6 only). Block #8 can have 9 in 76, 95 or 96 (others are < constrained). So in the column 4 we don't have any 9 from blocks #2 and #8, so it must be in block #5, so you can directly put it into 54. Great! first placed number. :-D

mtronic:have troubles even placing the 9s

lono: did you get the 9s and need hint further or do you have troubles even placing the 9s?

mtronic:Thank you for the hint but I still cannot solve it

The <> rules are very important, you basically start with it, as the first numbers you place in are 9s and 1s.

So to make a hint, check all places where 9 can be and use sudoku rules to place almost all of them (7 of 9 iirc) and the rest will display two possible cells only. After the 9 placement there is one important decision based on the killer total value... (if you want I can hint little bit more :-)

And finally don't forget on the two main diagonals to contain all the 9 digits.

lono: I will send you step by step solving, but I must to do it first. ;-)