題目: A message containing letters from A-Z is being encoded to numbers using the following mapping way: 'A' -> 1
'B' -> 2
...
'Z' -> 26 Beyond that, now the encoded string can also contain the character ‘*’, whic
傳送門 Description Given an integer (signed 32 bits), write a function to check whether it is a power of 4. Example:Given num = 16, return true. Given num = 5, return false. Follow up: Could you solve it without loops/recursion? 思路 題意:不
LeetCode——Maximum Depth of Binary Tree Question 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 leaf node. Answer /*** Definition for a binary tree node