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24 lines
536 B
24 lines
536 B
9 years ago
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#find the longest collatz sequence under one million
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#if n is even n -> n/2
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#if n is odd n -> 3n + 1
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longest_sequence = 0
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matching_number = 0
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for i in range(1, 1000001):
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sequence_count = 0
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number = i
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while number != 1:
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if number % 2 == 0:
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number /= 2
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else:
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number *= 3
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number += 1
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sequence_count += 1
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if longest_sequence < sequence_count:
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longest_sequence = sequence_count
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matching_number = i
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print(longest_sequence)
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print(matching_number)
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