修修55

摘要： Sort a linked list in O(n log n) time using constant space complexity. 用mergeSort.快排的时间复杂度最差是n^2; 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. 阅读全文

摘要： Given a sorted linked list, delete all duplicates such that each element appear only once. For example, Given 1->1->2, return 1->2. Given 1->1->2->3-> 阅读全文

摘要： Remove all elements from a linked list of integers that have value val. Example Given: 1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6, val = 6 Return: 1 --> 2 阅读全文

摘要： Follow up: Could you do it in O(n) time and O(1) space?/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL... 阅读全文

摘要： /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */ class Solution { public: ListNode* r... 阅读全文

摘要： Example: Given 1->2->3->4->5->NULL, return 1->3->5->2->4->NULL. //The program should run in O(1) space complexity and O(nodes) time complexity. //Plea 阅读全文

摘要： Example: 阅读全文

摘要： Write a function to delete a node (except the tail) in a singly linked list, given only access to that node. Supposed the linked list is 1 -> 2 -> 3 - 阅读全文

摘要： 给定一个字符串，请你将字符串重新编码，将连续的字符替换成“连续出现的个数+字符”。比如字符串AAAABCCDAA会被编码成4A1B2C1D2A。 输入描述: 每个测试输入包含1个测试用例 每个测试用例输入只有一行字符串，字符串只包括大写英文字母，长度不超过10000。 阅读全文