Friday Puzzles #261

Hurray!  It's another Christmas Tree Sudoku!

• Givens take the shape of silly decorations.  There is nothing else to say about these.
• The tree (anything shaded green or brown) acts as a fortress.  Which is to say numbers placed in the fortress must be strictly greater than those placed in the immediately adjacent  cells outside the fortress;
• Silver circles (fairy lights?!  Tinsel!?!) marking some pairs of adjacent cells are as in Parity Sudoku.  Which is to say one of the numbers to be placed must be odd and the other must be even.  Not all such pairs are marked
• White circles (erm, stars!?) marking some pairs of adjacent cells mean the corresponding two numbers to be placed must be consecutive.  Not all such pairs are marked.

Nice and easy.  Enjoy!

   #300 Christmas Tree Sudoku – rated hard

All puzzles © Tom Collyer 2009-14.

Bonus Christmas Puzzle

The multi-talented Tiit Vunk shared a Christmas themed Sudoku puzzle on facebook the other day and it inspired me to try something in a similar vein.  So here goes!

The Christmas tree itself acts like a fortress.  That is, cells that are part of the Christmas tree must contain digits which are strictly large than digits in adjacent cells which are not part of the tree.  There is no restriction for two adjacent cells which are part of the tree.  Where there is potential ambiguity as to whether a cell is part of the tree, I've filled it with a pale yellow glow.

Each piece of tinsel on the tree indicates an ascending sequence of digits in the cells that it covers.  it's up to you to determine in which direction.  Hopefully it's clear where the tinsel is going.  Please note that some pieces of tinsel are going diagonally between cells.

Finally the tree is decorated with some baubles and a star.  These have no significance other than to provide givens for the puzzle.  Upon test solving in paint, I found these decorations to be somewhat distracting.  I should also add that I haven't tried printing this, so hopefully I've chosen a shade of green that doesn't come out too dark.  Then again you'll have to live with this.  It's a Christmas tree, see.

Oh, and this one isn't for the faint hearted in terms of its difficulty.  But not so hard that you'll need to guess.  But hey, you've all got tons of free time on your hands, right?  Merry Christmas, Dearest Reader, and as always, Enjoy!

    #225 Christmas Tree Sudoku – rated hard

All puzzles © Tom Collyer 2009-12.

Friday Puzzles #167

What do you know?  I've reached a landmark without realizing it and made a special for the occasion!

The grids from left to right are:  Classic Sudoku, Diagonal Sudoku, Windoku, Irregular Sudoku and Non-Consecutive Sudoku.  Where grid overlap, so do the extra rules (although note that this still means a digit in the irregular grid adjacent to the non-consecutive grid is allowed to be consecutive).  Enjoy!

    #200 Olympic Sudoku – rated hard

All puzzles © Tom Collyer 2009-12.