Code Notes

摘要： Implementatoito convert a string to an integer.Hint:Carefully consider all possible input cases. If you want a challenge, please do not see below and ... 阅读全文

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