# Problems

## Problems 2013-08-26

3D 4X4 Cube L(3,1) D(27,3,3,0,0,0)

Moderate

True 3 dimensional problem. Each 4X4 square is one plane of a 4X4X4 cube. Consider the squares stacked on top of each other. There are 12 planes in this problem each of which is a 4X4 square which must have no repeating characters. Some of the planes are highlighted. There are 16 possible characters so I use a standard hexadecimal character set: 0,1,2,…,9,a,…,f.

Backslash L(2,1) D(17,10,9,0,0,0)

Moderate

Must have unique characters in each row and column but the 3 by 3 boxes are replaced by backslashes. These wrap left to right and top to bottom so the overall geometry is a doughnut (torus)

Diamond L(2,1) D(22,6,5,0,0,0)

Moderate

Here the shapes are pushed over to become diamonds. This wraps side to side but not top to bottom.

People L(2,3) D(15,22,21,4,2,0)

Difficult

The shapes have “lumps” on each side to become quite irregular. They look to me like little people. This problem wraps top to bottom and side to side so the overall geometry is like a doughnut (torus).

Toroid V L(2,1) D(26,5,4,0,0,0)

Moderate

The normal 3X3 boxes are replaced by vertical stripes (helices) which wrap around the problem. These stripes join the left side to the right side and the top to the bottom so that the overall geometry is a doughnut (torus).

## Problems 2013-08-19

4X4 Cube L(3,1) D(40,7,6,0,0,0)

Moderate

Strictly a 2 dimensional problem since only considering the outside faces which are laid out onto a plain. There are 16 Characters which cannot repeat in any band or face. 3 of the bands are highlighted. There are 12 bands and 6 faces, each with 16 Cells. There are 16 possible characters so I use a standard hexadecimal character set: 0,1,2,…,9,a,…,f.

Backslash L(2,1) D(17,10,10,0,0,0)

Moderate

Must have unique characters in each row and column but the 3 by 3 boxes are replaced by backslashes. These wrap left to right and top to bottom so the overall geometry is a doughnut (torus)

Diamond L(2,1) D(22,4,4,0,0,0)

Moderate

Here the shapes are pushed over to become diamonds. This wraps side to side but not top to bottom.

Film L(2,1) D(22,11,10,0,0,0)

Moderate

Similar to the regular 9 by 9 Sudoku but the squares have lumps in the top and bottom. The problem wraps top to bottom but not side to side so the overall geometry is a cylinder.

Toroid H L(2,3) D(16,14,14,2,1,0)

Difficult

The normal 3X3 boxes are replaced by horizontal stripes (helices) which wrap around the problem. These stripes join the left side to the right side and the top to the bottom so that the overall geometry is a doughnut (torus).

## Problems 2013-08-12

4X4 Cube L(3,1) D(39,9,8,0,0,0)

Moderate

Strictly a 2 dimensional problem since only considering the outside faces which are laid out onto a plain. There are 16 Characters which cannot repeat in any band or face. 3 of the bands are highlighted. There are 12 bands and 6 faces, each with 16 Cells. There are 16 possible characters so I use a standard hexadecimal character set: 0,1,2,…,9,a,…,f.

Diamond L(2,1) D(22,7,6,0,0,0)

Moderate

Here the shapes are pushed over to become diamonds. This wraps side to side but not top to bottom.

Jigsaw L(2,1) D(22,6,5,0,0,0)

Moderate

As regular 9 by 9 but the normal 3X3 boxes are irregular shapes

People L(2,3) D(15,20,20,4,4,0)

Difficult

The shapes have “lumps” on each side to become quite irregular. They look to me like little people. This problem wraps top to bottom and side to side so the overall geometry is like a doughnut (torus).

Toroid V L(2,3) D(19,14,14,2,1,0)

Difficult

The normal 3X3 boxes are replaced by vertical stripes (helices) which wrap around the problem. These stripes join the left side to the right side and the top to the bottom so that the overall geometry is a doughnut (torus).

## Problems 2013-08-05

3D 4X4 Cube L(3,1) D(28,4,3,0,0,0)

Moderate

True 3 dimensional problem. Each 4X4 square is one plane of a 4X4X4 cube. Consider the squares stacked on top of each other. There are 12 planes in this problem each of which is a 4X4 square which must have no repeating characters. Some of the planes are highlighted. There are 16 possible characters so I use a standard hexadecimal character set: 0,1,2,…,9,a,…,f.

Diamond L(2,1) D(19,9,8,0,0,0)

Moderate

Here the shapes are pushed over to become diamonds. This wraps side to side but not top to bottom.

Film L(2,1) D(21,9,8,0,0,0)

Moderate

Similar to the regular 9 by 9 Sudoku but the squares have lumps in the top and bottom. The problem wraps top to bottom but not side to side so the overall geometry is a cylinder.

Jigsaw L(2,1) D(22,6,5,0,0,0)

Moderate

As regular 9 by 9 but the normal 3X3 boxes are irregular shapes

Toroid H L(2,2) D(20,14,13,2,0,0)

Difficult

The normal 3X3 boxes are replaced by horizontal stripes (helices) which wrap around the problem. These stripes join the left side to the right side and the top to the bottom so that the overall geometry is a doughnut (torus).

# Solutions

## Solutions 2013-08-26

## Solutions 2013-08-19

## Solutions 2013-08-12

## Solutions 2013-08-05