Irregular Skyscraper Sudoku Rules：
Skyscraper Sudoku contains clues around the edge. The task is to place digits in the grid. Each digit represents the height of the skyscraper in each cell. The numbers outside the grid represent the number of skyscrapers seen from the corresponding direction.
Irregular Skyscraper Sudoku Additional Rules：
Irregular Sudoku Rule: Each row, column, and irregularly shaped block must contain all the digits (1-9) without repetition. This is the key difference.
Skyscraper Sudoku combines the logic of regular Sudoku with a special rule based on visibility:
Regular Sudoku Rules Apply: Like regular Sudoku, each row, column, and 3x3 box must contain the digits 1 through 9 exactly once.
Skyscraper Clues: Numbers appear outside the grid, indicating how many digits are visible from that direction (row or column) if you imagine them as skyscrapers.
For example, a clue 3 next to a row means looking along that row, you should see exactly 3 digits without any other skyscrapers blocking your view.
Irregular Skyscraper Sudoku = Irregular Sudoku + Skyscraper Sudoku