Moscow Puzzles 89: Siskin and Thrush
Posted on Sat 30 October 2021 in tech • Tagged with programming, moscow puzzles, python
Moscow Puzzles #89
Siskin and Thrush
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| class birdcage: | |
| """ | |
| Moscow Puzzles 89 - Siskin and Thrush: | |
| At the end of summer camp the children decided to free the 20 birds they caught. | |
| Line up the cages in a row, counting from left to right, open each fifth cage with a bird in it. | |
| You may take the last two birds to the city. The children wanted to take Siskin and Thrush. | |
| Which cages should contain them? | |
| """ | |
| N = 20 | |
| SKIP = 5 | |
| def __init__(self): | |
| self.cage = [False] * self.N | |
| self.visited = set() | |
| self.total = set() | |
| for i in range(1, self.N+1): | |
| self.total.add(i) | |
| def iterate(self, pos): | |
| pos += 1 | |
| if pos == self.N+1: | |
| pos = 1 | |
| while pos in self.visited: | |
| pos += 1 | |
| if pos == self.N+1: | |
| pos = 1 | |
| return pos | |
| def skip_count(self): | |
| pos = 0 | |
| skcount = 0 | |
| while len(self.visited) < self.N - 2: | |
| if skcount < self.SKIP: | |
| skcount += 1 | |
| pos = self.iterate(pos) | |
| else: | |
| self.visited.add(pos) | |
| skcount = 0 | |
| return self.total - self.visited; | |
| if __name__ == '__main__': | |
| cage = birdcage() | |
| closed = cage.skip_count() | |
| print(closed) |
