Manacher
In plain terms
A linear-time algorithm to find the longest palindromic substring.
Going deeper
Manacher's algorithm finds all palindromic substrings in linear time by reusing previously computed palindrome information. It avoids redundant center expansions.
Under the hood
O(n) versus the naive O(n²); cleverly exploits palindrome symmetry to skip work.
Examples
Longest palindrome problems, string analysis, competitive programming.
Think of it like...
Like checking mirror-symmetry around each point but remembering earlier reflections to avoid rechecking.