James Pan

原题网址：https://leetcode.com/problems/implement-queue-using-stacks/mplement the following operations of a queue using stacks.push(x) -- Push element x to the back of queue.pop() -- Removes the

原题网址：https://leetcode.com/problems/reverse-nodes-in-k-group/Given a linked list, reverse the nodes of a linked list k at a time and return its modified list.If the number of nodes is not a m

原题网址：https://leetcode.com/problems/plus-one-linked-list/Given a non-negative number represented as a singly linked list of digits, plus one to the number.The digits are stored such that the most

原题网址：https://leetcode.com/problems/reverse-linked-list-ii/Reverse a linked list from position m to n. Do it in-place and in one-pass.For example:Given 1->2->3->4->5->NULL, m = 2 and n = 4,

原题网址：https://leetcode.com/problems/swap-nodes-in-pairs/Given a linked list, swap every two adjacent nodes and return its head.For example,Given 1->2->3->4, you should return the list as 2-

原题网址：https://leetcode.com/problems/reverse-integer/Reverse digits of an integer.Example1: x = 123, return 321Example2: x = -123, return -321click to show spoilers.Have you thought

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/invert-binary-tree/Invert a binary tree. 4 / \ 2 7 / \ / \1 3 6 9to 4 / \ 7 2 / \ / \9 6 3 1思路：递归调用，对左右子节

原题网址：https://leetcode.com/problems/reverse-vowels-of-a-string/Write a function that takes a string as input and reverse only the vowels of a string.Example 1:Given s = "hello", return "hol

原题网址：https://leetcode.com/problems/reverse-linked-list/Reverse a singly linked list.click to show more hints.Hint:A linked list can be reversed either iteratively or recursively. Could

原题网址：https://leetcode.com/problems/reverse-bits/Reverse bits of a given 32 bits unsigned integer.For example, given input 43261596 (represented in binary as 00000010100101000001111010011100)

原题网址：https://leetcode.com/problems/reorder-list/Given a singly linked list L: L0→L1→…→Ln-1→Ln,reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→…You must do this in-place without altering the nodes' va

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/reverse-string/Write a function that takes a string as input and returns the string reversed.Example:Given s = "hello", return "olleh".方法：循环。public c

原题网址：https://leetcode.com/problems/reverse-words-in-a-string-ii/Given an input string, reverse the string word by word. A word is defined as a sequence of non-space characters.The input stri

原题网址：https://leetcode.com/problems/binary-tree-upside-down/Given a binary tree where all the right nodes are either leaf nodes with a sibling (a left node that shares the same parent node) or em