摘要:
Given an integer, convert it to a roman numeral. Input is guaranteed to be within the range from 1 to 3999. Given an integer, convert it to a roman nu 阅读全文
摘要:
Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. 水题一枚,注意搞清楚规则,注意空间分配 class Solution { publi 阅读全文
摘要:
Given a binary tree, determine if it is a valid binary search tree (BST). Assume a BST is defined as follows: The left subtree of a node contains only 阅读全文