摘要： Given a string S and a string T, count the number of distinct subsequences of T in S. A subsequence of a string is a new string which is formed from t 阅读全文

摘要： Given an index k, return the kth row of the Pascal's triangle. For example, given k = 3,Return [1,3,3,1]. Note:Could you optimize your algorithm to us 阅读全文

摘要： Given numRows, generate the first numRows of Pascal's triangle. For example, given numRows = 5,Return 用的比价暴力的方法， 也是最快的。 阅读全文

摘要： Follow up for problem "Populating Next Right Pointers in Each Node". What if the given tree could be any binary tree? Would your previous solution sti 阅读全文

摘要： Given a binary tree Populate each next pointer to point to its next right node. If there is no next right node, the next pointer should be set to NULL 阅读全文

摘要： Given a binary tree, flatten it to a linked list in-place. For example,Given The flattened tree should look like: 这道题就是将数变为只有右节点的树。 递归，不是很难。 递归的时候求出左节 阅读全文