摘要：
Given a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top to bottom.For exam... 阅读全文
摘要：
Write a function to find the longest common prefix string amongst an array of strings. 1 class Solution { 2 public: 3 string longestCommonPrefix(v... 阅读全文
摘要：
Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.For example,"A man, a plan, a canal: Pana... 阅读全文
摘要：
Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.The brackets must close in the c... 阅读全文