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->1->4->3. Your algorithm should use only constant space. You may not modify the values in the list, onl…

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->1->4->3. Your algorithm should use only constant space. You may not modify the values in the list, onl…

Given a linked list, swap every two adjacent nodes and return its head. You may not modify the values in the list's nodes, only nodes itself may be changed. Example: Given 1->2->3->4, you should return the list as 2->1->4->3. 这道题不算难,是基本的…

Given a linked list, swap every two adjacent nodes and return its head. You may not modify the values in the list's nodes, only nodes itself may be changed. Example: Given ->->->, you should ->->->. 奇数位和偶数位互换,若是奇数个,不用管最后一个 解法一:(C++) List…

e.g. 给定链表 1->2->3->4,返回 2->1->4->3 的头节点. 我写了个常见的从头节点遍历,少量的奇数个或偶数个数据都能成功重新排列.但链表过长时结果显示 Time Limit Exceeded . ListNode* swapPairs(ListNode* head) { ListNode *p = head, *q, *pre; while (p) { if (q = p->next) { if (p == head) head = q; p…

Given a linked list, swap every two adjacent nodes and return its head.   Example Given 1->2->3->4, you should return the list as 2->1->4->3. Challenge Your algorithm should use only constant space. You may not modify the values in the l…

单链表是一种递归结构,可以将单链表看作特殊的二叉树(我把它叫做一叉树) 单链表的定义: /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */ 1. O(1)时间删除结点 ListNode* DeleteNode(ListNode* pHead, ListNode* dele…

Requests 网络资源(URLs)撷取套件 改善Urllib2的缺点,让使用者以最简单的方式获取网络资源 可以使用REST操作(POST,PUT,GET,DELETE)存取网络资源 import requests newsurl='http://www.sina.com.cn/' res=requests.get(newsurl) print(res)#<Response [200]> print(res.encoding)#单字节编码ISO-8859-1 res.encoding='ut…

Given a binary tree, flatten it to a linked list in-place. For example,Given 1 / \ 2 5 / \ \ 3 4 6 The flattened tree should look like: 1 \ 2 \ 3 \ 4 \ 5 \ 6 click to show hints. Hints: If you notice carefully in the flattened tree, each node's right…

Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from 1 to 3999. 之前那篇文章写的是罗马数字转化成整数(http://www.cnblogs.com/grandyang/p/4120857.html), 这次变成了整数转化成罗马数字,基本算法还是一样.由于题目中限定了输入数字的范围(1 - 3999), 使得题目变得简单了不少. 基本字符 I V…