This problem follows the Find Mid + Reverse + Merge pattern, commonly found in the Linked List category. Recognizing this pattern is key to solving it efficiently in an interview setting.
Find middle, reverse second half, merge the two halves alternately.
Three classic operations combined: find middle (fast/slow), reverse list (iterative), merge two lists (interleave). Master these individually.
# Find middle
slow = fast = head
while fast.next and fast.next.next:
slow = slow.next
fast = fast.next.next
# Reverse second half
second = reverse(slow.next)
slow.next = null
# Merge alternating
first = head
while second:
tmp1, tmp2 = first.next, second.next
first.next = second
second.next = tmp1
first, second = tmp1, tmp2Practice Reorder List and similar Linked List problems with flashcards. Build pattern recognition through active recall.
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