绿树荫

摘要： Sort a linked list using insertion sort.思路一：使用一个dummy node，将就的节点插入到新的链表中即可。 1 public ListNode insertionSortList(ListNode head) { 2 ListNode du... 阅读全文

摘要： Given two integersnandk, return all possible combinations ofknumbers out of 1 ...n.For example,Ifn= 4 andk= 2, a solution is:[ [2,4], [3,4], [2,3],... 阅读全文

摘要： Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the root node of a BST.Callingnext()will return the next... 阅读全文

摘要： Given a string containing just the characters'('and')', find the length of the longest valid (well-formed) parentheses substring.For"(()", the longest... 阅读全文