In a grid of 6 by 6 squares you need to place a skyscraper in each square with only some clues:
- The height of the skyscrapers is between 1 and 6
- No two skyscrapers in a row or column may have the same number of floors
- A clue is the number of skyscrapers that you can see in a row or column from the outside
- Higher skyscrapers block the view of lower skyscrapers located behind them
To understand how the puzzle works, this is an example of a row with 2 clues. Seen from the left there are 6 buildings visible while seen from the right side only 1:
| 6 | 1 |
|---|
There is only one way in which the skyscrapers can be placed. From left-to-right all six buildings must be visible and no building may hide behind another building:
| 6 | 1 | 2 | 3 | 4 | 5 | 6 | 1 |
|---|
Input: The clues in an array of 24 items ordered around the clock. Index:
| 0 | 1 | 2 | 3 | 4 | 5 | ||
|---|---|---|---|---|---|---|---|
| 23 | 6 | ||||||
| 22 | 7 | ||||||
| 21 | 8 | ||||||
| 20 | 9 | ||||||
| 19 | 10 | ||||||
| 18 | 11 | ||||||
| 17 | 16 | 15 | 14 | 13 | 12 |
- If no clue is available, add value
0 - Each puzzle has only one possible solution
Output: Array of skyscrapers heights linewise (top to bottom, left to right).
| 2 | 2 | ||||||
|---|---|---|---|---|---|---|---|
| 5 | 6 | 1 | 4 | 3 | 2 | ||
| 4 | 1 | 3 | 2 | 6 | 5 | ||
| 3 | 2 | 3 | 6 | 1 | 5 | 4 | |
| 6 | 5 | 4 | 3 | 2 | 1 | 6 | |
| 4 | 1 | 2 | 5 | 6 | 4 | 3 | 3 |
| 4 | 3 | 4 | 2 | 5 | 1 | 6 | |
| 4 |
Input: '0,0,0,2,2,0,0,0,0,6,3,0,0,4,0,0,0,0,4,4,0,3,0,0'
Output: '5,6,1,4,3,2,4,1,3,2,6,5,2,3,6,1,5,4,6,5,4,3,2,1,1,2,5,6,4,3,3,4,2,5,1,6'