647. Palindromic Substrings

Medium

Given a string, your task is to count how many palindromic substrings in this string.

The substrings with different start indexes or end indexes are counted as different substrings even they consist of same characters.

Example 1:

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Input: "abc"
Output: 3
Explanation: Three palindromic strings: "a", "b", "c".

Example 2:

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Input: "aaa"
Output: 6
Explanation: Six palindromic strings: "a", "a", "a", "aa", "aa", "aaa".

Note:

解法1

动态规划：

时间复杂度：O(n²) 空间复杂度：O(n²)