走走停停的专栏

题目描述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 algorithm should use only con...

题目描述Given a sorted linked list, delete all duplicates such that each element appear only once.For example,Given1->1->2, return1->2.Given1->1->2->3->3, return1->2->3.题目大...

题目描述Given a binary tree, return the bottom-up level order traversal of its nodes’ values. (ie, from left to right, level by level from leaf to root).For example:Given binary tree{3,9,20,#,#,15,7},...