Code Notes

摘要：Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.For example,"A man, a plan, a canal: Pana... 阅读全文

摘要：Given a string containing just the characters'(',')','{','}','['and']', determine if the input string is valid.The brackets must close in the correct ... 阅读全文

摘要：1) Dequeue can quickly insert or delete both at the front or the end. However, vector can only quickly insert or delete at the end.2) Memory allocatio... 阅读全文

摘要：The string"PAYPALISHIRING"is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font fo... 阅读全文

摘要：Given a singly linked list where elements are sorted in ascending order, convert it to a height balanced BST.分析：我们比较熟悉由一个sorted array生成一个BST，不同的是这里的数据... 阅读全文

摘要：A linked list is given such that each node contains an additional random pointer which could point to any node in the list or null.Return a deep copy ... 阅读全文

摘要：Sort a linked list using insertion sort.分析：insertion sort是将当前元素插入到已经排好序的元素的适当位置，时间复杂度为O(n^2)。class Solution {public: ListNode *insertionSortList(Li... 阅读全文

摘要：Given a linked list, return the node where the cycle begins. If there is no cycle, returnnull.Follow up:Can you solve it without using extra space?分析：... 阅读全文

摘要：Given a linked list, determine if it has a cycle in it.Follow up:Can you solve it without using extra space?分析：如果一个linked list中有环，那么在用一个快指针和一个慢指针遍历该li... 阅读全文

摘要：Mergeksorted linked lists and return it as one sorted list. Analyze and describe its complexity.分析：一个很简单的解法是调用k-1次merge two sorted linkedlist，假设每个list... 阅读全文

摘要：Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.代码：class ... 阅读全文

摘要：Given a linked list and a valuex, partition it such that all nodes less thanxcome before nodes greater than or equal tox.You should preserve the origi... 阅读全文

摘要：Given a sorted linked list, delete all nodes that have duplicate numbers, leaving onlydistinctnumbers from the original list.For example,Given1->2->3-... 阅读全文

摘要：Given a linked list, remove thenthnode from the end of list and return its head.For example, Given linked list: 1->2->3->4->5, and n = 2. After re... 阅读全文

摘要：Given a singly linked listL: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' values.For exam... 阅读全文

摘要：Reverse a linked list from positionmton. Do it in-place and in one-pass.For example:Given1->2->3->4->5->NULL,m= 2 andn= 4,return1->4->3->2->5->NULL.No... 阅读全文

摘要：Given a linked list, reverse the nodes of a linked listkat a time and return its modified list.If the number of nodes is not a multiple ofkthen left-o... 阅读全文

摘要：Given a list, rotate the list to the right bykplaces, wherekis non-negative.For example:Given1->2->3->4->5->NULLandk=2,return4->5->1->2->3->NULL.分析：此题... 阅读全文

摘要：Sort a linked list inO(nlogn) time using constant space complexity.分析：merge sort。class Solution {public: ListNode *sortList(ListNode *head) { ... 阅读全文

摘要：Given a linked list, swap every two adjacent nodes and return its head.For example,Given1->2->3->4, you should return the list as2->1->4->3.Your algor... 阅读全文

摘要：You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single ... 阅读全文

摘要：Given a sorted linked list, delete all duplicates such that each element appear onlyonce.For example,Given1->1->2, return1->2.Given1->1->2->3->3, retu... 阅读全文