摘要：
Reverse a linked list. For linked list 1->2->3, the reversed linked list is 3->2->1 Reverse it in-place and in one-pass 用两个指针可以做到。这种链接的在纸上先用图形+语句画好很有帮 阅读全文
摘要：
Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest l 阅读全文