James Pan

原题网址：https://leetcode.com/problems/strobogrammatic-number-ii/A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down).Find all strobogrammati

原题网址：https://leetcode.com/problems/longest-palindromic-substring/Given a string S, find the longest palindromic substring in S. You may assume that the maximum length of S is 1000, and there e

原题网址：https://leetcode.com/problems/palindrome-number/Determine whether an integer is a palindrome. Do this without extra space.click to show spoilers.Some hints:Could negative integers

原题网址：https://leetcode.com/problems/shortest-palindrome/Given a string S, you are allowed to convert it to a palindrome by adding characters in front of it. Find and return the shortest palindrom

原题网址：https://leetcode.com/problems/scramble-string/Given a string s1, we may represent it as a binary tree by partitioning it to two non-empty substrings recursively.Below is one possible

原题网址：https://leetcode.com/problems/symmetric-tree/Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).For example, this binary tree is symmetric:

原题网址：https://leetcode.com/problems/palindrome-pairs/Given a list of unique words. Find all pairs of distinct indices (i, j) in the given list, so that the concatenation of the two words, i.e.

原题网址：https://leetcode.com/problems/palindrome-partitioning-ii/Given a string s, partition s such that every substring of the partition is a palindrome.Return the minimum cuts needed for a pa

原题网址：https://leetcode.com/problems/line-reflection/Given n points on a 2D plane, find if there is such a line parallel to y-axis that reflect the given set of points.Example 1:Given po

原题网址：https://leetcode.com/problems/strobogrammatic-number-iii/A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down).Write a function to co

原题网址：https://leetcode.com/problems/strobogrammatic-number/A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down).Write a function to determ

原题网址：https://leetcode.com/problems/populating-next-right-pointers-in-each-node/Given a binary tree struct TreeLinkNode { TreeLinkNode *left; TreeLinkNode *right; TreeLinkN

原题网址：https://leetcode.com/problems/palindrome-permutation/Given a string, determine if a permutation of the string could form a palindrome.For example,"code" -> False, "aab" -> True, "ca

原题网址：https://leetcode.com/problems/palindrome-permutation-ii/Given a string s, return all the palindromic permutations (without duplicates) of it. Return an empty list if no palindromic permut

原题网址：https://leetcode.com/problems/reverse-words-in-a-string/Given an input string, reverse the string word by word.For example,Given s = "the sky is blue",return "blue is sky the".U

原题网址：https://leetcode.com/problems/palindrome-partitioning/Given a string s, partition s such that every substring of the partition is a palindrome.Return all possible palindrome partitionin

原题网址：https://leetcode.com/problems/valid-palindrome/Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.For example,"A man, a plan,

原题网址：https://leetcode.com/problems/bulb-switcher/There are n bulbs that are initially off. You first turn on all the bulbs. Then, you turn off every second bulb. On the third round, you toggle e

原题网址：https://leetcode.com/submissions/detail/58253344/Given a singly linked list, determine if it is a palindrome.Follow up:Could you do it in O(n) time and O(1) space?思路：普通的思路是可以生成一个反转的

原题网址：https://leetcode.com/problems/valid-word-square/Given a sequence of words, check whether it forms a valid word square.A sequence of words forms a valid word square if the kth row and co