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25 lines
821 B
HTML
25 lines
821 B
HTML
<p>Given a circular linked list, implement an algorithm that returns the node at the beginning of the loop.</p>
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<p>Circular linked list: A (corrupt) linked list in which a node's next pointer points to an earlier node, so as to make a loop in the linked list.</p>
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<p><strong>Example 1: </strong></p>
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<pre>
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<strong>Input: </strong>head = [3,2,0,-4], pos = 1
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<strong>Output: </strong>tail connects to node index 1</pre>
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<p><strong>Example 2: </strong></p>
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<pre>
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<strong>Input: </strong>head = [1,2], pos = 0
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<strong>Output: </strong>tail connects to node index 0</pre>
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<p><strong>Example 3: </strong></p>
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<pre>
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<strong>Input: </strong>head = [1], pos = -1
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<strong>Output: </strong>no cycle</pre>
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<p><strong>Follow Up: </strong><br />
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Can you solve it without using additional space?</p>
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