Hot100: Palindrome Linked List Fast/Slow + Reverse Second Half O(1) Space ACERS Guide
Subtitle / Summary The core of palindrome validation is symmetric comparison, but a singly linked list cannot move backward. The most stable engineering template is: find middle -> reverse second half in-place -> compare -> reverse back to restore. Reading time: 10-14 min Tags: Hot100, linked list, fast slow pointers, in-place reverse SEO keywords: Palindrome Linked List, fast slow pointers, reverse second half, O(1) space, LeetCode 234 Meta description: O(n)/O(1) palindrome check for singly linked list with middle detection, second-half reversal, comparison, and full structure restoration. A - Algorithm (Problem and Algorithm) Problem Restatement Given the head of a singly linked list head, return true if it is a palindrome; otherwise return false. ...