dropout一般用于全连接层，因为全连接层是推断，按照已有特征推断，drop之后特征不足，强制新特征学习。而conv层是特征提取的过程，drop会降低特征提取能力（略显牵强。。。）。以上只是强行解释。

Given a binary search tree with non-negative values, find the minimum absolute difference between values of any two nodes.

Given a word, you need to judge whether the usage of capitals in it is right or not.

We define the Perfect Number is a positive integer that is equal to the sum of all its positive divisors except itself.

Given scores of N athletes, find their relative ranks and the people with the top three highest scores, who will be awarded medals: "Gold Medal", "Silver Medal" and "Bronze Medal".

第一个while之后的if else语句作用是将mid放到指定位置(不会再变的位置), 完成左右划分,左边都是<mid,右边都是>=mid.

已知中序+后序, 重建 按照图示顺序, 从根写起, 依靠中序分割左右两侧, 逐步重建.后序较前序稍微难一点点(只不过是从右往左), 故给出这一个典型例子足矣. 已知前序+后序不足以重建 如: {代码...} 这两个树的前序和后序是一致的, 因此只知道前后序无法精确重建!

Given a binary search tree (BST) with duplicates, find all the mode(s) (the most frequently occurred element) in the given BST.

Given a non-empty string check if it can be constructed by taking a substring of it and appending multiple copies of the substring together. You may assume the given string consists of lowercase English letters only and its length will not exceed ...

Given a List of words, return the words that can be typed using letters of alphabet on only one row's of American keyboard like the image below.

You are given two arrays (without duplicates) nums1 and nums2 where nums1’s elements are subset of nums2. Find all the next greater numbers for nums1's elements in the corresponding places of nums2.

Find the largest palindrome made from the product of two n-digit numbers.

Given a positive integer, output its complement number. The complement strategy is to flip the bits of its binary representation.

Given a positive integer, output its complement number. The complement strategy is to flip the bits of its binary representation.

Given an array of integers where 1 ≤ a[i] ≤ n (n = size of array), some elements appear twice and others appear once.

Given a string s and a non-empty string p, find all the start indices of p's anagrams in s.

You are given a binary tree in which each node contains an integer value.

Given two non-negative integers num1 and num2 represented as string, return the sum of num1 and num2.

Given a non-empty array of integers, return the third maximum number in this array. If it does not exist, return the maximum number. The time complexity must be in O(n).

Given a string which consists of lowercase or uppercase letters, find the length of the longest palindromes that can be built with those letters.