Approach Summary
Expand around each center (n odd-length centers + n-1 even-length centers). Count each valid expansion.
How to Recognize This Pattern
- Count palindromic substrings, not just longest
- Expand-around-center: O(n²) time, O(1) space
Complexity Analysis
Time Complexity
O(n²)
Space Complexity
O(1)
Tags
String Dynamic Programming