Steps for Toroidal 12X12

(Logic and images from Prasanna)

Step 1 : The 8 and 9 clues for row4&5 takes up 17 cells. Whatever way it goes since it cant form a loop around the grid, 2 cells space will remain empty. So you have 11 columns to fit in 17 snake cells. In every 2 columns, you can have maximum 3 snake cells. So 10 columns can have max 15. One extra column will have both snake cells. So it is a complete zig zag configuration.		Step 2 : Since it forms a zig zag path, there will be only one exit from row4/5. And it has to be towards row 3 because the 1 clue of row 3 can not be satisfied otherwise.
Step 3 : The snake can not go up from R4C3, because of the 3 clue in that column. So you can complete the Zig Zag configuration. In column 1, 7 of the remaining 8 cells are to be snake parts. So exactly one will not be snake part. If both R1C1 and R2C1 are snake parts, the 4 of row2 can not be satisfied. [ There are 2 cases if both the cells are snake cells. These 2 cases are shown in 2 different images ]
Step 4 : So now row 7 to row 12 of column 1 are snake parts.		Step 5 : Some standard book-keeping stuff.
Step 6		Step 7
Step 8		Step 9

Solutions appended to puzzle booklet.

Congrats to EKBM, Uvo and Deu for top 3 places. congrats to Prasanna, Amit and Swaroop for top 3 India. Thanx to all 173 participants.

Thanks to deb for giving me the opportunity to conduct the contest. the contest was on a tough side. Toroidal seemed to be the toughest in this contest. there were 22 participants who submitted all the 22 puzzles correctly :)
hoped u all enjoyed the contest. Thanks

Steps for Snake - 1

1. The snake has not go up from R7C5, otherwise the 6 clue of row 6 can not be satisfied.
2. At R6C5, the snake has to turn right.

Steps for Snake - 2

If the snake passes through R3C1, that end will meet R2C3. No further snake parts are possible in the right side region, so the 3s of R2/3/4 can not be satisfied.

Steps for Snake - 3

Steps for Snake - 4