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문제 링크 Kth Smallest Element in a BST - LeetCode Can you solve this real interview question? Kth Smallest Element in a BST - Given the root of a binary search tree, and an integer k, return the kth smallest value (1-indexed) of all the values of the nodes in the tree. Example 1: [https://assets.leetco leetcode.com 풀이 # Definition for a binary tree node. # class TreeNode: # def __init__(self, val=0..

문제 링크 Palindromic Substrings - LeetCode Can you solve this real interview question? Palindromic Substrings - Given a string s, return the number of palindromic substrings in it. A string is a palindrome when it reads the same backward as forward. A substring is a contiguous sequence of character leetcode.com 풀이 class Solution: def countSubstrings(self, s: str) -> int: n = len(s) # 문자열의 길이를 구하기 d..

You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise). You have to rotate the image in-place, which means you have to modify the input 2D matrix directly. DO NOT allocate another 2D matrix and do the rotation. Example 1: Input: matrix = [[1,2,3],[4,5,6],[7,8,9]] Output: [[7,4,1],[8,5,2],[9,6,3]] Example 2: Input: matrix = [[5,1,9,11],[2,4,8,10],[13,3,..