# QA Official

### 115. Distinct Subsequences

https://qaofficial.com/post/2019/04/27/73524-115.-distinct-subsequences.html 2019-04-27
Given a string S and a string T, count the number of distinct subsequences of T in S. A subsequence of a string is a new string which is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (ie, “ACE” is a subsequence of “ABCDE” while “AEC” is not). Here is an example:S = “rabbbit”, T = “rabbit”

[force] thread pool is not allowed to be created by using Executors, but by using ThreadPoolExecutor.This kind of processing method makes students who write more clear about the running rules of thread pool and avoids the risk of resource exhaustion. Let's talk about the disadvantages of the four thread pools created by Executors. Because thread pools created by Executors do not pass in the rejection policy parameter but use the

### Oracle Tree Statistics-Child Nodes Aggregated to Parent Nodes

https://qaofficial.com/post/2019/04/27/73544-oracle-tree-statistics-child-nodes-aggregated-to-parent-nodes.html 2019-04-27
Initial tree data state:|--2(0)--4(100)0--1(0)--| |--3(0)--5(200) Summarized Tree Data Status:|--2(100)--4(100)0--1(300)--||--3(200)--5(200)create table t(id number,parent_id number,value number);insert into t values(1,0,0);insert into t values(2,1,0);insert into t values(3,1,0);insert into t values(4,2,100);insert into t values(5,3,200);commit;SQL> select * from t order by id asc;ID PARENT_ID VALUE---- ---------- ----------1 0 02 1 03 1 04 2 100 5 3 200 SQL> with ttt as (select t.*,SYS_CONNECT_BY_PATH(id,'/')||'/' pathfrom t start with t.parent_id=0 connect by prior t.

### R language convesio of jsonfiles to csv or rdatformat

https://qaofficial.com/post/2019/04/27/73501-r-language-convesio-of-jsonfiles-to-csv-or-rdatformat.html 2019-04-27

### ResNet Interpretation

https://qaofficial.com/post/2019/04/27/73472-resnet-interpretation.html 2019-04-27

### ResNet Realize 150-Layer deep neural network Image Recognition

https://qaofficial.com/post/2019/04/27/73332-resnet-realize-150-layer-deep-neural-network-image-recognition.html 2019-04-27
The traditional neural network is difficult to do very deep, because gradient explosion or gradient disappearance will occur, resulting in difficult convergence. ResNet has some "shortcuts" in each layer, which makes it possible to do many layers. In this paper, a 150-layer neural network is implemented to recognize gesture images, and the training time is acceptable. Data Set Download Address: http://pan.baidu.com/s/1bpo8DEv The program can only be run after downloading the

### Ubuntu 16.04 Unable to Install Third Party deb Software Solution

https://qaofficial.com/post/2019/04/27/73475-ubuntu-16.04-unable-to-install-third-party-deb-software-solution.html 2019-04-27
Solution Referred to Wind-Like Programmers Ubuntu 16.04 comes with a software center that is probably problematic. The third player software is rarely installed successfully and the solution is relatively simple. Let's change to a software management tool. first, we install gdebi. sudo apt install gdebi-core 安装好gdebi以后，从终端进入到待安装软件包所在

### controller cannot get the value configured by @Value-spring parent-child container

https://qaofficial.com/post/2019/04/27/73732-controller-cannot-get-the-value-configured-by-value-spring-parent-child-container.html 2019-04-27
In the controller, the @Value annotation cannot get the value, but the \${key} string is directly output. Reason: the project is configured only in applicationContext.xml and not in spring-mvc.xml Resolution: corresponding container scans configuration files written with property or the parent container is injected to obtain the attribute, and getter and setter methods are provided to the outside, and the child container is obtained through the getter method analysis:

### scikit-learn chinese document cross-validation-unsupervised learning | apachcn

https://qaofficial.com/post/2019/04/27/73846-scikit-learn-chinese-document-cross-validation-unsupervised-learning-apachcn.html 2019-04-27
chinese document: http://sklearn.Apache cn.org/cn/stable/modules/cross _ validation.html english document: http://sklearn.Apache cn.org/en/stable/modules/cross _ validation.html Official Document: http://scikit-learn.org/stable/ github: https://github.com/apachecn/scikit-learn-doc-zhStar, we have been working hard) Contributor: https://github.com/apachecn/scikit-learn-doc-zh# Contributor About Us: http://www.apachecn.org/organization/209.html Note: This document is being translated...