Qgfzzzzzz

Given a non-empty array of integers, every element appears twice except for one. Find that single one.Note:Your algorithm should have a linear runtime complexity. Could you implement it without us...

Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.Note: For the purpose of this problem, we define empty string as valid palindrome.Examp...

The count-and-say sequence is the sequence of integers with the first five terms as following:1. 12. 113. 214. 12115. 1112211 is read off as "one 1" or 11.11 is read off a...

In a row of trees, the i-th tree produces fruit with type tree[i].You start at any tree of your choice, then repeatedly perform the following steps:Add one piece of fruit from this tree to your ba...

2019/3/25栈84 柱状图中最大的矩形树对称二叉树