猫酱

摘要： 题目 Given an integer array nums, find a contiguous non-empty subarray within the array that has the largest product, and return the product. It is guar 阅读全文

摘要： 题目 You are given an array prices where prices[i] is the price of a given stock on the iᵗʰ day. Find the maximum profit you can achieve. You may comple 阅读全文

摘要： 题目 Given an integer n, return the least number of perfect square numbers that sum to n. A perfect square is an integer that is the square of an intege 阅读全文

摘要： 题目 Given the root of a binary tree, determine if it is a valid binary search tree (BST). A valid BST is defined as follows: The left subtree of a node 阅读全文

摘要： 题目 Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree. According to the definition of LCA on Wikipedia: “The lo 阅读全文

摘要： 题目 Given two integer arrays preorder and inorder where preorder is the preorder traversal of a binary tree and inorder is the inorder traversal of the 阅读全文

摘要： 题目 数字 n 代表生成括号的对数，请你设计一个函数，用于能够生成所有可能的并且 有效的 括号组合。 有效括号组合需满足：左括号必须以正确的顺序闭合。 示例 1： 输入：n = 3 输出：["((()))","(()())","(())()","()(())","()()()"] 示例 2： 输入： 阅读全文

摘要： 快排算法 时间复杂度：O() 空间复杂度：O() public class QuickSort { public static void main(String[] args) { int[] num = {3,45,78,64,52,11,64,55,99,11,18}; System.out.p 阅读全文

摘要： 题目 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 substri 阅读全文

摘要： 题目 Given a string s, return the longest palindromic substring in s. Example 1: Input: s = "babad" Output: "bab" Note: "aba" is also a valid answer. Ex 阅读全文