45 lines
812 B
Python
45 lines
812 B
Python
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def fibonacci_generator():
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"""
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Fibonacci generator function that starts with 1, 1, 2, 3, ...
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:returns: generator that yields fibonacci numbers
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"""
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a = 0
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b = 1
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yield b
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while True:
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a, b = b, (a + b)
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yield b
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def fibonacci_generator_smaller(n):
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"""
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:param n: generator yields all fibonacci numbers smaller n
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:returns: generator that yields fibonacci numbers
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"""
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g = fibonacci_generator()
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x = next(g)
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while x < n:
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yield x
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x = next(g)
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def fibonacci_nth(n):
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"""
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:param n: index of fibonacci that should be returned
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:returns: nth fibonacci number
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"""
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if n < 1:
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return 0
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g = fibonacci_generator()
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i = 1
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x = next(g)
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while i < n:
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i += 1
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x = next(g)
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return x
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