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23 lines
458 B
Ruby
23 lines
458 B
Ruby
def palindrome?(head)
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stack = []
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slow_runner = fast_runner = head
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while !fast_runner.nil? && !fast_runner.next.nil?
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stack.push(slow_runner.val)
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fast_runner = fast_runner.next.next
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slow_runner = slow_runner.next
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end
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unless fast_runner.nil?
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slow_runner = slow_runner.next
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end
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until slow_runner.nil?
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temp = stack.pop
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return false unless slow_runner.val == temp
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slow_runner = slow_runner.next
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end
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true
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end
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