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[!info] related notes 算法面试题型 MOC

Linked List Interview Patterns

Intersection of Two Acyclic Lists

• Let the longer list advance abs(lenA - lenB) steps first.
• Then move both pointers together; the first equal node is the intersection.

Reverse Nodes in k-Group

• Pattern: locate a k-sized block, reverse it, connect tail to next block.
• Key: you need the previous block’s tail to reconnect.

Copy List with Random Pointer

• Common patterns:
  • HashMap old->new.
  • Interleaving nodes (clone node inserted after original) then split.

Palindrome List

• Fast/slow pointers find middle.
• Reverse second half.
• Compare two halves.
• Optional: restore the list by reversing back.

// compare halves after reversing from mid
// (template only; adapt to your ListNode definition)

Cycle Entry Node

• HashSet method: record visited nodes.
• Floyd method:
  • First meet: fast and slow.
  • Then set one pointer to head, both move 1 step; next meet is the entry.

Related

• 双指针