ROUND 42020

WPF PUZZLE GP 2020INSTRUCTION BOOKLET

Host Country: BulgariaDeyan Razsadov

Special Notes: None.

1. Gaps (No touch) (12 points)

Points:

1. Gaps (No touch) 12

2. Blokus (Tetriminoes) 9

3. Blokus (Pentominoes) 18

4. Four Winds 21

5. Spans 26

6. Skyscrapers 20

7. Skyscrapers (Full Evens) 28

8. Snake (Ends) 34

9. Snake (Ends,Striped) 54

10. Star Battle 41

11. Arrows 125

12. Neighbors 27

13. Neighbors 45

14. Japanese Sums 54

15. Japanese Sums (Hitori) 46

16. Magnets 48

17. Yajilin 84

TOTAL: 692

Blacken some cells in the grid such that each row and each column contains exactly two blackened cells. The numbers to the left of (or above) the grid indicate the number of unblackened cells between the blackened cells in that row (or column). Blackened cells may not touch each other, not even diagonally.

The numbers on the far top of the diagram are for Answer purposes only.

Answer: For each row from top to bottom, enter the number of the first column from the left where a blackened cell appears (the number on the far top of that column). Use only the last digit for two-digit numbers; e.g., use ‘0’ if the first blackened cell appears in column 10.

Example Answer: 273151626 1 2 3 4 5 6 7 8 9

6

7

4

2 7 3 1 5 1 6 2 6

10 1 2 3 4 5 6 7 8 9

6

7

45

2020ROUND 4WPF PUZZLE GP

2. Blokus (Tetriminoes) (9 points)

3. Blokus (Pentominoes) (18 points)

Shade some cells black so that the black cells form the shapes of seven different tetriminoes. Each tetrimino shape is used exactly once. Shapes can be rotated but not reflected. Tetriminoes cannot touch along edges, but can touch at corners. If a corner is marked with a dot, then two tetriminoes touch at that corner. If a corner is not marked with a dot, then two tetriminoes do not touch at that corner.

Answer: For each designated row, enter the letter for each tetrimino that appears in that row, from left to right. Within a row, if a tetrimino occupies more than one cell, only enter that tetrimino’s letter once. If there are no tetriminoes in that row, enter a single letter ‘A’.

Example Answer: TO,LZS

Shade some cells black so that the black cells form the shapes of twelve different pentominoes. Each pentomino shape is used exactly once, but can be rotated or reflected. Pentominoes cannot touch along edges, but can touch at corners. If a corner is marked with a dot, then two pentominoes touch at that corner. If a corner is not marked with a dot, then two pentominoes do not touch at that corner.

Answer: For each designated row, enter the letter for each pentomino that appears in that row, from left to right. Within a row, if a pentomino occupies more than one cell, only enter that pentomino’s letter once. If there are no pentominoes in that row, enter a single letter ‘A’.

Example Answer: YWLU,PXI

V

X

T

U

I

WL

P

ZF

N

Y

6a

6b

6a

6b

T

I

LJ

O

SZ

2

2

2

2

T

ILJ

O

S Z

V

X

T

U

I

W

LP

Z

F

N

Y

2020ROUND 4WPF PUZZLE GP

4. Four Winds (21 points)

5. Spans (26 points)

Draw arrows in the empty cells in the grid. Arrows can only go in the four standard directions and must begin at the edge of a cell with a number. Each empty cell must be covered by exactly one arrow. Each number indicates the total length of all the arrows that begin at an edge next to that number’s cell.

The dots in cells are only used for entering your answers.

Answer: Enter the number whose arrow covers the dot, reading the dots from left to right. (Ignore which row the dots are in.) Use only the last digit for two-digit numbers; e.g., use ‘0’ for a number labeled 10.

Example Answer: 62224

Draw a horizontal or vertical line segment in every white cell in the grid. Each number indicates the total number of line segments that are connected to that numbered cell (line segments connect other line segments that share an end).

The dots in cells are only used for entering your answers.

Answer: Enter the sum of all numbers connected to the line segment in the cell with the dot (but not going through other numbers), reading the dots from left to right. (Ignore which row the dots are in.) Use only the last digit for two-digit numbers; e.g., use ‘0’ if the sum is10. If no numbers are connected to the line segment, enter ‘0’.

Example Answer: 52206

2 4 3 2 6 2

6 2 2 2 413

2 4 3 2 6 2

13

6 2 0 2 3 2 1

5 2 2 0 613

6 2 0 2 3 2 1

13

2020ROUND 4WPF PUZZLE GP

6. Skyscrapers (20 points)

7. Skyscrapers (Full Evens) (28 points)

Place a number from 1 to X (integers only) into each cell so that each number appears exactly once in each row and column. (X is the number of cells in each row.) Each number represents a skyscraper of its respective height. The numbers outside the grid indicate how many skyscrapers can be seen in the respective row or column from the respective direction; smaller skyscrapers are hidden behind higher ones. Some numbers may already be filled in for you.

Answer: For each designated row, enter its contents. Do not include any numbers outside the grid.

Example Answer: 45312,23541

Place a number from 1 to X (integers only) into each cell so that each number appears exactly once in each row and column. (X is the number of cells in each row.) Each number represents a skyscraper of its respective height. The numbers outside the grid indicate how many skyscrapers can be seen in the respective row or column from the respective direction; smaller skyscrapers are hidden behind higher ones. Some numbers may already be filled in for you.

All possible even numbers outside the grid are provided.

Answer: For each designated row, enter its contents. Do not include any numbers outside the grid.

Example Answer: 4231,1423

1 3 4

3 2

2

Skyscraper Clue Examples

4 5 3 1 2 5 4 1 2 3 1 2 4 3 5 2 3 5 4 1 3 1 2 5 4

5 3 3 4 3

4 2

3a

3b

5 3 3 4 3

4 2

3a

3b

3 1 4 2 4 2 3 1 2 3 1 4 1 4 2 3

2 4 2 2 2

2 2 2

7a

7b

2 4 2 2 2

2 2 2

7a

7b

1 3 4

3 2

2

Skyscraper Clue Examples

2020ROUND 4WPF PUZZLE GP

8. Snake (Ends) (34 points)

9. Snake (Ends,Striped) (54 points)Locate a “snake” in the grid. The snake is a path that starts in a cell, goes through some number of cells orthogonally, and ends in a cell. The snake cannot go through any cells marked with ‘×’. Each cell is used at most once by the snake. The snake may not loop around to touch itself, not even diagonally. (In other words, if two cells in the snake touch orthogonally, then they must be exactly one cell apart along the path of the snake, and if two cells in the snake touch diagonally, then they must be exactly two cells apart along the path of the snake.)

The snake is colored with two alternating colors such that each cell in the snake is a single color and cells that touch along an edge are different colors. Numbers to the left of the grid (if given) indicate how many snake cells in that row are the same color as the snake’s ends (including the ends themselves). Numbers above the grid (if given) indicate how many snake cells in that column are of the other color.

The two cells containing the ends of the snake are shaded.

Answer: For each designated row, enter its contents. Use O for a cell occupied by the snake and X for a cell not occupied by the snake. Alternatively, you may use any two distinct characters instead of ‘XO’.

Example Answer: XXXXO,OOOXO

Locate a “snake” in the grid. The snake is a path that starts in a cell, goes through some number of cells orthogonally, and ends in a cell. The snake cannot go through any cells marked with ‘×’. Each cell is used at most once by the snake. The snake may not loop around to touch itself, not even diagonally. (In other words, if two cells in the snake touch orthogonally, then they must be exactly one cell apart along the path of the snake, and if two cells in the snake touch diagonally, then they must be exactly two cells apart along the path of the snake.) Numbers outside the grid, if given, indicate how many cells in that row or column are occupied by the snake.

The two cells containing the ends of the snake are shaded.

Answer: For each designated row, enter its contents. Use O for a cell occupied by the snake and X for a cell not occupied by the snake. Alternatively, you may use any two distinct characters instead of ‘XO’.

Example Answer: OOXXX,XXXOO

0 1

3

1 0 2 1 0 2

7a

7b

0 1

3

1 0 2 1 0 2

7a

7b

1 2 2 4 2 4 2

7a

7b

1 2 2 4 2 4 2

7a

7b

2020ROUND 4WPF PUZZLE GP

10. Star Battle (41 points)

11. Arrows (125 points)

12-13. Neighbors (27, 45 points)

1 2 3 4 5 6 7 8 9

2 6 1 6 2 7 1 3 5

4aPlace stars into some cells in the grid, no more than one star per cell. Each row, each column, and each outlined region must contain exactly two stars. Cells with stars may not touch each other, not even diagonally.

The numbers on top of the diagram are for Answer purposes only.

Answer: For each row from top to bottom, enter the number of the first column from the left where a star appears (the number on top of that column). Use only the last digit for two-digit numbers; e.g., use ‘0’ if the first star appears in column 10.

Example Answer: 261627135

Draw an arrow in each of the empty cells outside the main grid. Each arrow must point in one of the eight standard directions, and must point to at least one numbered cell. Each numbered cell must be pointed at by exactly that number of arrows.

Answer: The contents of indicated rows, from left to right. Use ‘A’ for an arrow pointing diagonally left, a ‘B’ for an arrow pointing orthogonally, and ‘C’ for an arrow pointing diagonally right. Alternatively, you may use any three characters instead of ‘ABC’ , as long as they are distinct.

Example Answer: CACCA,BCAAA

Place one of the digits 1, 2, or 3 into each cell, one digit per cell, so that each digit appears the same number of times in each row and column. Some digits may already be placed for you. After placing all digits, each white cell must touch at least one cell with the same number along an edge, and each gray (outlined) cell must not touch any cells with the same number along an edge.

Answer: For each designated row, enter its contents.

Example Answer: 133213212,322131231

3 3 1 4 2 4 1 5 1 2 5 6 2 4 3 4 2 2 1 2 2 1 3 2 1

3 3 1 4 2 4 1 5 1 2 5 6 2 4 3 4 2 2 1 2 2 1 3 2 1

3 2 2 1

1 1 2 3

1 3 1 3 2 2 1 3 2 2 1 2 2 3 1 3 1 3 3 2 3 1 2 3 1 2 1 1 3 3 2 1 3 2 1 2 2 1 2 3 1 2 3 1 3 3 2 3 1 2 1 3 2 1 3 2 2 1 3 1 2 3 1 2 3 1 3 1 3 1 2 2 1 1 1 2 3 2 2 3 3

8a

8b

3 2 2 1

1 1 2 3

8a

8b

1 2 3 4 5 6 7 8 9

4a

2020ROUND 4WPF PUZZLE GP

14. Japanese Sums (54 points)

15. Japanese Sums (Hitori) (46 points)

Place a digit from the specified list into some cells so that no digit appears more than once in each row or column. Cells may remain empty. Numbers outside the grid indicate all sums of continuous groups of digits (including “sums” of a single digit) along that row or column. These groups are separated by empty cells. These sums are given in the same order as their corresponding groups of digits.

Some sums are not given to you and represented by a question mark (‘?’). These sums must contain at least one digit.

All digits must be connected orthogonally and no two empty cells are adjacent orthogonally.

Answer: For each designated row, enter its contents, using ‘X’ for an empty cell.

Example Answer: 4X512X,X4X5X3

Place a digit from the specified list into some cells so that no digit appears more than once in each row or column. Cells may remain empty. Numbers outside the grid indicate all sums of continuous groups of digits (including “sums” of a single digit) along that row or column. These groups are separated by empty cells. These sums are given in the same order as their corresponding groups of digits.

Answer: For each designated row, enter its contents, using ‘X’ for an empty cell.

Example Answer: 7X1X4,127X5

? ? 5 ? 11 ? 11 ? 5 11 ? 8 ? ? 4 7 5 6 ? ? ? ? ? ? 3 ?

3 1 2 5 3 2 1 5 4 5 1 2 1 5 4 3 2 4 5 3 5 2 1 3 4

{1–5}

7a

7b

? ? 5 ? 11 ? 11 ? 5 11 ? 8 ? ? 4 7 5 6 ? ? ? ? ? ? 3 ?

{1–5}

7a

7b

3 11 6 13 2 19 1 24 7 8 18 7 1 4 10 5 5 14

3 4 2 6 7 5 4 2 7 1 4 1 2 7 5 5 6 1 7

{1–7}

1a

1b

3 11 6 13 2 19 1 24 7 8 18 7 1 4 10 5 5 14

{1–7}

1a

1b

2020ROUND 4WPF PUZZLE GP

16. Magnets (48 points)

17. Yajilin (84 points)

The grid is partitioned into regions of two square cells each (note that only region borders are drawn). Put “positive” (+) and “negative” (–) symbols into some cells, at most one symbol per cell, such that each region either has two symbols or no symbols at all. Adjacent cells (even within a region) cannot contain the same symbol.

The numbers above and to the left of the grid indicate the exact number of symbols of the specified type that must be placed in each column or row, respectively. If a number is not given, there might be any number of symbols of the specified type.

The dots in cells are only used for entering your answer.

Blacken some white cells and then draw a single closed loop through all remaining white cells. The loop may not intersect itself, go through a cell corner, or go through a cell more than once. The loop must go through the center of every cell it goes through and all turns in the loop must be at cell centers. Blackened cells cannot share an edge with each other. Some cells are outlined and in gray and cannot be part of the loop. Numbered arrows in such cells indicate the total number of blackened cells along the direction of the arrow, starting in the arrowed cell and going along a row or column to the edge of the grid.

The numbers on top of the diagram are for Answer purposes only.

+ 2– 0 3

0 1

2 2

2 3

P X P X N P13

– + – + – + – – + – + + + – + – + –

+ 2 – 0 3 0 1

2 2

2 3

13

1 2 3 4 5 6

21 0

4a

0 3 5 3 5 3

3

1 2 3 4 5 6

21 0

4a3

Answer: Enter the contents of each dotted cell, reading the dots from left to right. (Ignore which row the dots are in.) Use ‘P’ for a “positive” (+) symbol, ‘N’ for a “negative” (–) symbol, and ‘X’ for an empty cell. Alternatively, you may use any three characters instead of ‘PNX’ , as long as they are distinct.

Example Answer: PXPXNP

Answer: For each row from top to bottom, enter the column number of the left-most blackened cell. (Outlined gray cells are not blackened.) Use only the last digit for two-digit numbers; e.g., use ‘0’ for column 10. If none of the cells in a row are blackened, enter ‘0’ for that row.

Example Answer: 035353