78 lines
1.7 KiB
Python
78 lines
1.7 KiB
Python
import math
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class Tree:
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def __init__(self, value, children):
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self.value = value
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self.children = []
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for child in children:
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self.children.append(Tree(child, []))
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def step(self):
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if len(self.children) == 0:
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for val in step(self.value):
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self.children.append(Tree(val, []))
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return
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for child in self.children:
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child.step()
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def __str__(self):
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retval = '[' + str(self.value) + ': '
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for child in self.children:
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retval += str(child)
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retval += ']'
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return retval
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def __repr__(self):
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return str(self)
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def longest_path(self):
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if len(self.children) == 0:
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return [self.value]
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max_path = []
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max_length = 0
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for child in self.children:
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temp = child.longest_path()
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if len(temp) > max_length:
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max_path = temp
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max_length = len(temp)
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return [self.value] + max_path
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def is_square(x):
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return int(math.sqrt(x)) == math.sqrt(x)
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primes = {}
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def is_prime(x):
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try:
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return primes[x]
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except KeyError:
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if x < 2:
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primes[x] = False
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return False
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i = 2
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while i * i <= x:
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if x % i == 0:
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primes[x] = False
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return False
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i += 1
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primes[x] = True
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return True
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def step(x):
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new_xs = []
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for i in range(10):
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if is_prime(10 * x + i):
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new_xs.append(10 * x + i)
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return new_xs
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def main():
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tree = Tree(0, [])
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for i in range(9):
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print(tree.longest_path())
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tree.step()
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print(tree.longest_path())
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if __name__ == '__main__':
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main()
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