摘要： tesetset 阅读全文

摘要： Pick One Given a string S and a string T, count the number of distinct subsequences of S which equals T. A subsequence of a string is a new string whi 阅读全文

摘要： Given a binary tree, flatten it to a linked list in-place. For example, given the following tree: The flattened tree should look like: 将一个二叉树变成一个链表形式的 阅读全文