Palindromic Substrings
Part of Practice: Strings & Coins
Given a string s, count how many of its substrings are palindromes — strings that read the same forwards and backwards. Substrings at different positions count separately even when their text is identical: "aa" contains the substring "a" twice, and each occurrence counts.
Constraints: 1 <= s.length <= 1000, lowercase letters only.
Examples
- Input:
- s = "abc"
- Output:
- 3
Only the single characters qualify: "a", "b", "c".
- Input:
- s = "aaa"
- Output:
- 6
Three single "a"s, two "aa"s (positions 0-1 and 1-2), and one "aaa".
Hints
One at a time — struggle first, peek second.
Your thinking space — verify on LeetCode, then mark it.