Saturday, June 30, 2018

Leetcode 308: Range sum query 2D - Mutable

June 30, 2018


It is also a good idea to work on three hard level algorithm a day, one for morning, one for afternoon, one for evening. There are over 150 hard level algorithms, it is a good idea to stay updated with Leetcode.

One idea I got from the peer before is to read the problem statement first, do not look at the answer, let myself to think about the algorithm at least 20 minutes.

Here is the blog related to the algorithm.

Quick study

It is related to binary index tree. I read the blog 10 minutes, and I also plan to read discussion panel for one or two solutions. That is it.

Here is very good link to read from Leetcode discussion. And then I found a good article to read as well.

Island count

June 30, 2018


It is my 4:00 PM mock interview. I had to work on the algorithm called Island count. After I explained the algorithm to the peer, peer asked me if I like to continue to write the code for the solution, or I like to discuss with the extended algorithm. I chose to discuss the extended algorithm.

Extended algorithms 

I was asked to work on the extended algorithm. Here is the transcript for our discussion. I need to write code for those two extended algorithms.

Follow up No. 1

Follow up No. 2


It is also a good idea to work on the feedback from the peer.

My feedback to the peer

Here is my feedback.

Leetcode 304: Range Sum Query 2D - Immutable

June 30, 2018


Plan to read discussion of the algorithm. Here is the link.

Design a function from matrix region sum to jigsaw problem

June 30, 2018


It is my most favorite algorithm back in 2015. I had this algorithm exactly same one in 2015. It is called to calculate the subarea sum of matrix.

Here are a few resources.

1. matrix region sum
2. My practice on June 25, 2015, matrix region sum
3. My blog about the algorithm, June 25, 2015. The blog is here. I made a few corrections to make the blog more readable.
4. My blog on April 26, 2016, here is the link.
5. Leetcode 304 - Range Sum query 2D - Immutable

Jigsaw problem 

I recently worked on the design of a jigsaw problem. And also I had discussion with two peers. We tried to identify the problem as a classical algorithm. What is the brute force solution? what can we do better.

I read my solution and I think that it is still a brute force solution. If the function is called a lot of times, we need to reduce the time complexity.

Here is my code written less than a month.

What is the time complexity of my solve function? I put preprocessing function inside the solve function. That is a mistake since it defines time complexity to O(row * row * column * column).

The code was written but time complexity is defined by preprocessing function, which is the bigger one.
The solution I think will be better if I remove the preprocessing and build a dictionary outside the function. We only need to do it once. Therefore the time complexity of solve function can be lowered to O(rows * columns) since it takes O(1) time to get every piece's four neighbors.

Actually the second for loop on line 30 should include all pieces except itself.

Chris Everest

June 30, 2018


I start to learn from tennis professional one a time. Chris evert used to be a Wimbledon champion. It is my favorite video, even though it is commercial one. Here is the link.

Friday, June 29, 2018

A quick study - Li na back in 2013 to change coach to get help win second grand slam

June 28, 2018


Once a while when I get frustrated, I will start to do some short study on tennis sports. One thing is to find out how the player to replace coach, what are those factors to be considered.

One article 10 minute read

Here is the article I read. I will put down some notes here.

Thursday, June 28, 2018

Let us get it loud - hard level algorithm names

June 28, 2018


It is one of Jennifer Lopez's song called "Let us get it loud". I like to play when I try to warm up before I go out to play tennis. I like to use this song to help me to memorize hard level algorithms on

Here is all the list of hard algorithms on  I just could not believe that I can just read those names over 30 minutes non-stop, and enjoy to read those names.

It is such an interesting study of those hard level algorithm names. They are very well titled and make a short story just using a few words.

Name a few good names of hard level algorithms

One thing  I can do is to list some algorithm names and explain how good the names are. Let me come out a few ideas how to memorize those names, maybe most frequent words in those titles.

I plan to add some notes for each hard level algorithm on Here is the pdf file I work on.

Follow up 

Sept. 5, 2018

I started to work on easy level algorithms on starting from July 10, 2018. There are 190 easy level algorithms for me to work on first.

It is the attitude change. I like to take the advice from my personal coach, and I start to build a good habit to write code every day, busy working on easy level algorithms for a few months.

Once I master the basics, it will not be tough for me to work on hard level algorithms.

Dijkstra's algorithm study

June 28, 2018


It is one of medium algorithm on Hackerrank week of code 38 called "A time-saving affair". I learned from the editorial note that it is related to Dijkstra's algorithm.

I did not have time to look into graph algorithm last Sunday since I ran out of time to play. I just wrote code and then tried to get any point on this algorithm, last hour I score 0 point on the algorithm and tried to improve my algorithm, only two test cases time out. I scored almost full score on the algorithm.

Time to look into timeout issue

I plan to study the algorithm and find out the timeout issue.

How to get motivated to get a gold medal on week of code?

June 28, 2018


It is 11:19 PM, and I just finished one hour mock interview with a young graduate from 10:00 PM to 11:00 PM. I like to choose a small topic and conduct 20 minutes study. The topic is how to get motivated to get a gold medal on week of code?

A few thoughts

I can get a gold medal only if I can find time and work a lot of hours for week of code contest on I need to do a lot of research and search related algorithm on for those hard level and advanced level algorithms.

Sometimes I need to learn how to motivate myself to play hard on the contest. Recently I spent a lot of hours to get organized on my past hackerrank contests on github. I did spend some time to go over those contests and tried to review those blogs as well.

It is so enjoyable to play Hackerrank contest and keep improving my performance. I like those long hours hard work. Very good feelings to get involved in problem solving.

Follow up 

July 13, 2018
8:10 PM
I should work on 10 algorithms on Hackerrank Euler before I play next contest. In order to get gold medal, I have to catch up practice on those algorithms with a lot of mathematics. Just a thought.

Try to get two role models from those players on Hackerrank Eulers.

First medal in 2018, Bronze medal

June 28, 2018


It is time for me to celebrate small success for week of code 38 bronze medal today. I was waiting for the bronze  medal since this Monday. I did write a blog called tangible goals, I like to achieve small goals first and help me to get back on track.

I should push myself hard and work on the contest last Saturday, so I could have enjoyed the time to solve hard level and expert level algorithm. Every time I have problems to solve the hard level algorithm, I find myself so happy to spend hours to study and try to solve the problem. Even scoring 0 will make me so happy. I just like to learn something new.

Keep good habit

It is good idea to keep good habit and do not give up. It takes time to build up a good habit. It is like sports training, once I have so many good friends on tennis court. It is so easy for me to go out to play tennis.

I have built a few good habits to do things last 18 months. I have weekend day for whole day mock interviews. I have good habit to keep being interviewer last 6 months to be an interviewer.

I need to build a new habit for one weekend day for courses, one weekend day for Those are two new habits I like to have.

Let us get all facts together

I score 10% of whole 300 points.
I played last day of week of code 38 only.
I got last hour to push myself from bottom 20% to top 25%
Here is the comparison to rank no. 1
Here is the folder to contain all three algorithms I solved

Last Saturday I did not work on the contest, why?
Motivation issues - what to work on? How to motivate myself to get a Gold medal?
Easy level second algorithm, I only scored 30% all possible points I could get

30 minutes to study leadboard of Canada
One profile with Hackerrank solution on is here.

Wednesday, June 27, 2018

Leetcode 124: Binary tree maximum path sum

June 27, 2018


It is the hard level algorithm and it should be very good exercise for me to work on. I plan to work on it in short future.

My past practice can easily be looked up here.

I like to look into Leetcode discussion and try to get more ideas how to solve the algorithm.

A good friend like me

June 27, 2018


It is the first time I like to do a small research on this topic. What is most advantage to be a blogger? I know that I am not the best talent software engineer in the world. But I can tell that two friends are most talent software engineers in the world, I connect both of them through blogging, and then we had discussion on the algorithms. I listened how those two communicated and tried to learn as much as I can.

A good friend like me

How do top two talent people meet? they know me first, and I make connections and set up a meeting together. This is the first meeting. I just could not believe that I did such a fantastic job.

Celebrate with one algorithm

I like to celebrate the friendship using one algorithm called mine sweeper. Here is the transcript. 

Tuesday, June 26, 2018

Celebrate 52 times as an interviewer

June 26, 2018


It is time for me to celebrate my work 10:00 PM as an interviewer, I just finished my 52th interview as an interviewer.

My advice

I had good time to discuss the algorithm with the interviewee today using Leetcode maximum sliding window. It is hard level algorithm.

The interviewee is new master graduate and he asked me what advice I have for him.

Here are the advice I give to him today.

800 Leetcode algorithm, work on hard level 170

   1. try to remember all hard level question names
   2. second try to read all the hard level questions
   3. third try to memorize best time complexity of algorithm

My argument

My argument is based on the fact that those interviewer from Facebook, Amazon, Google are somehow very nice, they just choose one hard level algorithm from 170 Leetcode hard level algorithms. So if you are hard working enough, you may just memorize all of them. You only need to get the idea, and then work hard to figure out the detail in 10 to 20 minutes. 

Monday, June 25, 2018

10 times more efficient programmer

June 25, 2018


It is interesting topic how to be 10 times more efficient. I know that in tennis sports, professional tennis player can hit hard and run fast then me at least 3 times. I did go through the stage to learn by myself through youtube video, and I used to allow the tennis racquet hit my head and arm and leg a few times when I played against the wall, and I tried to swing too hard to control of tennis racquet. There is risk to advance skills by just trying.

Just be normal

I think that I can write very readable and clean code. But I have issues to come out ideas how to solve the hard level algorithm. So I have to design drills to help me think hard, think more thorougly.

Good thinking starts from basic exercise. I like to get familiar with those problems and start to remember names first.

Three drills to help me solve hard level algorithms

simple drill 

It is to remember the hard level algorithm name.

It is a new drill for me. What I do is to read each Leetcode hard level algorithm title, and then try to remember those names.

Next drill

I like to read hard level algorithm problem statement one by one. Try to understand the problems first.

Third drill

Start to think about ideas, using one sentence to describe the solution.

Week of code contest 38 was my best therapy

June 25, 2018


A coding contest can play an important role to help me enjoy a weekend. I just could not believe that my confidence comes back after the contest.

I like to do a small research to compare last Saturday to last Sunday. I felt that I did better last Sunday, since I committed to the week of code 38 contest, I like to play the contest and win a medal. Actually I tried to get into top 25%.

How does our brain work in order to achieve something? I definitely felt that last Sunday was more enjoyable since I worked on coding from 8:00PM to 11:50 PM more than three hours. Long hours working on an algorithm really brought so much fun to my peaceful life.

I did more than two hours coding in the morning for two easy level algorithms as well. So more than 5 hours coding really brought a lot of joy to my day. I am a software programmer who is calm and with discipline, willing to clean up code and write simple code. I was so proud of myself to be patient to go over the code and do some reasoning, patiently go over debugging process to fix a few bugs in the medium algorithm using Queue, a graph algorithm.

Also miracle happened, last one hour in the contest I fixed the bug of medium algorithm, scored points from zero point a few time to almost full points.

Progress report

I really love to play contest and write algorithm for a medium level algorithm. I wish that I can start early so I have time to work on hard level algorithm in the weekend instead.

C# IEqualityComparer interface

June 25, 2018


I cannot believe how busy I am last eight years. I never have chance to read the interface IEqualityComparer and learn how to use it. The C# foundation including ASP.NET is something I have to work hard to learn first, before I apply to work and also maintain the software.

It is the time for me to catch up learning and I like to understand object-oriented design through those C# class. Ask questions and write down here.

C# HashSet class

June 25, 2018


It is the algorithm called Sudoku solver, my favorite one. I did have a mock interview on June 23, 2018. I wrote C# solution and came cross the question, do HashSet class have Remove API. I notice that it is time for me to spend time to memorize all APIs of C# HashSet class.

HashSet class

There are so many things to do once I decide to start to memorize HashSet class.

I plan to study IEqualityComparer interface, and then I read HashSet source code.

I will write down all API here. It is important to try to memorize all API first. And then I should come out questions to ask about class design, implementation detail.

Follow up 

7 constructors

HashSet<T>(IEnumerable<T>, IEqualityComparer<T>)
HashSet<T>(Inte32, IEqualityComparer<T>)
HashSet<T>(SerializationInfo, StreamingContext)




CopyTo(T[]) - it is convenient to call - to array is so easy
CopyTo(T[], Int32)  - copies the elements of a HashSet<T> object to an array, starting at the specified array index
CopyTo(T[], Int32, Int32)
Static - CreateSetComparer() - it takes me more than 10 minutes to read - ask why it is static?
ExceptWith(IEnumerable<T>) - Removes all elements in the specified collection from the current HashSet<T> object.
Virtual - Finalize() - understand why it is virtural ?

GetEnumerator() - Returns an eneumerator taht iterates through a HashSet<T> object
GetObjectData(SerializationInfo, StreamingContext)
GetType() - Gets the Type of the current instance.
IntersectWith(IEnumerable<T>) - Modifies the current HashSet<t> object ot contain only elements that are present in that object and in the specified collection.
IsProperSubsetOf(IEnumerable<T>) - Determines whether a HashSet<T> object is a proper subset of the specified collection
IsProperSupersetOf(IEnumerable<T>) - supset

20 minutes study

Plan to spend 20 minutes quick study of five categories of types

GetType() - Gets the Type of the current instance.
Spend 10 minutes to read the code using GetType()

Classes -> System.Object
Value types -> System.ValueType
Interfaces - System.Object
Enumerations - System.Enum
Delegates -> System.MulticastDelegate

10 minutes to read

IsProperSubsetOf API docuement is here.

Questions asked:

Why CreateSetComparer() is static?
Why Finalize() is virtual?
what is proper subset? subset vs proper subset?

Min to win it - week of code 38

June 25, 2018


Life is so busy. It is hard to get into a fight against time out issue in the algorithm problem solving. I know that I have to get more training through hackerrank contest.

I spent over one hour to work on the code. I just could not figure out how to get linear time complexity going and then I decided to move to next algorithm around 3:00 PM this afternoon.

Time out so many test cases

Here is the image to show so many timeout test cases.

Sunday, June 24, 2018

I am back to hard working

June 24, 2018


It is so hard for me to go back to be a hard working programmer. It took me more than three weeks. I spent two days sitting at home the whole weekend, worked inside home office. First day it was Saturday, I did not want to go out, but I did not work on week of code 38 either.

Second day, I told myself to hold on everything just to play week of code 38. I only wrote first two algorithm less than three hours, one friend asked me to mock interview with him. It was maybe 5PM, I had discussion with him until 6:40 PM.

I was so patiently to go back to work on the third algorithm. Now it is 11:47 PM. I only worked on the contest less than 12 hours. Now I finally figured out the third algorithm even though I had to go over discussion panel to read all the discussion to figure out two user cases. I made it from score 0 to full score.

It took me almost one hour to read the problem statement of A time-saving affair, after one hour just thinking about the algorithm, I started to code and try to make any point if I can.

Love is patience 

Since I love algorithm and data structure challenge, I learn to be so patient to myself. I just let myself to enjoy the time to think, time to write code, hold on worry about scoring zero, and read the problem statement and search discussion for tips patiently. I know that the English wording in the problem statement is questionable. I just need ideas to think about the constraint different viewpoints.

I just gave myself enough time and let my brain think and try to write some code, simplify and make it work.

Now I push myself rank to top 25%.

I need to plan ahead and work in weekdays, and allow myself to work on hard level, advanced level and expert level in weekends.

I really enjoyed the time to write around 100 lines of code for the medium level algorithm. Finally I am back to normal, hard working, do not think about anything else.

I should write a medium/ hard level algorithm daily, otherwise I am very easy to get lazy.

Action Items

Julia, you should try to work on hard level and advanced level algorithm after the contest. Try to get out of comfortable zone and start to learn some hard level algorithm.

Follow up

My feelings of working on medium algorithm:

I need to expedite the thinking process. It is too slow. It is just a medium level algorithm.

I could not pass all test cases since timeout on second easy level algorithm.

If I like to pass onsite interview from SDE III, I have to push myself hard when I practice.

In terms of Hackerrank contest, I should be able to solve medium level algorithm without any headache. Those long hours to work on one medium level algorithm is alarm for me, I have to come out a plan to work on something. It should be less than two hours. 15 minutes to think about problem at most, not over one hour.

Replay of the last hour of contest

I finished the code passing the sample test case, but scored 0. I had only less than two hours to the end of contest. Maybe it is one hour only. I tried to push hard to figure out the issue.

I read the problem statement for a few times. And then I started to notice my design issues.

I already made sure that there is no dead loop. I still missed the issue, that is the best time to play contest after long hour. I showed up determined, very careful to scrutinize all possible issues.

I just like to use two graphes to show those kinds of experience are really healthy to train my mental toughness. I think that all the training and good habit to deal with uncertainty helped me in those 20 to 30 minutes to push hard.

I just showed those two images here and then memorized those hard working moments. The thing I could control very well, I should focus on. I start to realize my value of time of one hour in this critical moment. From bottom 15% to top 25% in the one hour.

Onsite interview algorithms

June 24, 2018


It is hard to pass phone screen. Once it is onsite, I think that most of people will have no clue to stay there sometimes, even smartest person will fail somehow. I came cross this post to discuss his experience. Here are the type of questions showing onsite.

binary search
sliding window
Topological sort,
two pointers,
bit manipulations,
data structure to implement LRU, LFU, stack/ queue, Trie, Sorting, design a data structure

Share one post after a few month break on

June 24, 2018


It took me more than one hour to write a post on I like to share something after a few months break. It is not too hard but it is not too easy. I try to make sense on each good thing, I write 10 good things. It is kind of too generic topic, 10 good things. Maybe I should write 3 good things next time, so I can save some time to work on something else.

what are ten good things after playing hackerrank contests?

I put together a question and then write an answer for it with supporting documents, I did add foot notes with more than 8 blogs I wrote before related to contests I played.

Here is the link on

Artificial intelligence article

June 24, 2018


I try to be a good friend to support those people staying in California and looking for a software engineer job. I also learn something every time a friend chats with me and update me some article to read.

I got an article to read and I like to scan the article and look into a few thing. Here is the article link.

20 minutes study

Luke Zettlemoyer, a professor at the University of Washington

AI Lab called Deep mind.

Study Linkedin profile - Marcelo M De Barros

June 23, 2018


I came cross the message since I follow the profile of Linkedin from Microsoft principle group manager Marcelo. It is so inspiring to study the profile with the summary.

I like to make similar presentation like Marcelo does. I believe that he has great taste of art.

My most favorite one is to read his coding blog. The link is here.

Saturday, June 23, 2018

Learn from Naomi Osaka

June 23, 2018


I gave myself several hours to study WTA ranking top 100, I did come cross some new faces and then look into a few players. And then I spent over 50 minutes to talk to a friend. And then I decided to study the player Naomi Osaka, how she tries to get into top 20 ranking.


It is fun to watch some interviews. I like to cheer myself up this Saturday. I do not know what to do in terms of study of top 100 ranking.

Here is the video called Naomi Osaka - Roland Garros Tennis Channel Desk visit.

1:11/ 2:40
What do you learn from yourself from victories?
Answer: Kind of surprise.

Plan to read the article called Naomi Osaka is the coolest thing in tennis.
Plan to read the article 10 minutes called

Naomi Osaka success shows tennis can be a better spectacle without seeding

Try to be consistent - Train very hard off the season - paying off - unsatisfied everything I do -
6:00 - train very hard off the season
7:00 -
8:00 -
9:00 - celebrate crazy way is kind of disrespect to the opponent
10:00 -
11:00 -
12:00 -
13:00 -
14:00 - 

10 minutes video:
BNP Paribas Open 2018: Naomi Osaka Champion's Press Conference

1:10           lose points depends on nerves (?)
2:09/10:49 psycho myself out, nerve get checked
3:31           ...
4:27           habits? think - more confident will win again
6:00           my goal - more focus each match
8:23           hit harder? ...         

Here is one of videos I like to play a few times.

Follow up

Sept. 8, 2018 6:11 PM

I just could not believe that I just watched Naomi won US open 2018 champion through video.

Ten good things about playing hackerrank contests

June 23, 2018


It is time for me to write down an eulogy about Hackerrank contest. I spent a lot of time to check in all source code for each hackerrank contest last week, and I just wondered how come I played so many contests through last two years.

It takes me hours to go over those algorithms, blogs. I could not believe that I did write so many algorithms, over 100 algorithms for over 25 contests.

Hackerrank contests

I used to play a lot of hours tennis sports. I know that people will ask me how many hours I have played. 500 hours or 1000 hours. I like to get those hours for Hackerrank contest.

I like to give thanks to Hackerrank and those sponsored companies. I never made it to any of those companies. I try to play for Canada, play for myself, and play for fun.

It is a new life style when I chose to play hackerrank contest one after another one. I could not remember I spent so many weekends to play contests.

Here are some facts:

1. 5 medals, including a gold medal, two silver medals, 2 bronze medals from March to June 2017.
2. A few calls from local software companies first time contacted me from July 2017 to Oct. 2017. 
3. April 2018 I got contact by a company, May I got a phone screen without code screen.
4. I play very well a lot of places. I think that I play Hackerrank,,, Code review on, mock interview platform, also social websites:,,, google+.

Here are my thoughts:

1. I want to be an excellent algorithm and data structure teacher.
2. I want to write code in the weekends. Keep myself busy.
3. I try to bring some topics for my coding blog, contest is really great activity.
4. From April to June, I had more time to play contests since I also play a lot of sports, tennis. 

We got so many platforms to play, somehow I just demonstrated to people that every one can do such a good job if you can work hard continuously over years. I also need to remind myself to work hard, do not give up.

Best thing is to love writing software after those contest experience. I just could not believe that I enjoy so much to write software at work. I could not control to rewrite if I have time, since I have better idea to implement a solution.

10 good things about playing contests

1. No more phone call, chatting.
2. No more shopping around. I try to cut down to minimum.
3. No worry about weather. Stay at home office all the time.
4. Enhance the ability to do research, enjoy exploring new topic of algorithm and data structure.
5. Know more players in the world.
6. New way to meet people, those people loving the competitions.
7. Do not need money to play. Only need free time.
8. Enjoy long hours work, I documented each hour. Work on a check list.
9. Build strong interesting to write code
10. Learn to play with limited time, follow up with code review questions, experience learning through more than 12 months.


Byte to byte - Algorithm and data structure problem solving coaching

June 23, 2018


I met a young graduate student and we worked together on mock interview algorithms 90 minutes. I worked on Sudoku solver, and he worked on binary search Array index and Element equality. He recommended me to watch Byte to Byte video on

It is such a good conversation with the young graduate, we did talk about a little theory about binary search algorithm, common mistakes, base case, dead loop, and lowest index, recursive function vs iterative solution.

And we talked about more about internship, onsite interviews. I really learn a few things about young graduate  student, a very good engineer and quick to write and work on coding all the time. Compared to him, I am kind of slow to get along with the peer, and not so good to work on a test case, and try to figure out things on the fly, make thing work.

One fact is that I practice binary search last 6 month over 50 times through mock interview, the peer only did once. I did see a lot of issues in the coding part. But I also learn how to judge a person with good thinking process and how to take hint and move forward. I treat the algorithm problem solving likes sports, there is no way to avoid hard work. Embrace it.


Academic research is such a great topic and I wish that I have time to get into more on a topic.

One video to watch

Here is five minutes called "Increasing your creativity and solve any coding interview problem".

Spend 15 minutes to go over all possible solutions first. We should not go to optimal solution right away.

Take the time to really think and even wild ideas. What sort of things will work, what sort of things will not work.

learn from one engineer - Tan chao

June 23, 2018


I read the article on, and came cross the name called 覃超.

20 minutes study

Here is the video I watched. 5 minutes video is here. 25 minutes video is here, the topic is things learned in the facebook.

Book to read: Find strengths 2.0

One argument is to work hard, you can do the best.

Every one should find yourself the strong five personalities.

Prioritize your tasks
Have your vision
Keep practicing
Watch replay

Reading time -

June 23, 2018


I understand that I need to catch up a lot of reading. One time my coach showed me how he came out an algorithm for me to work on since he saw a post on, so he just changed the phrase. The algorithm is here.

Saturday reading 

Here is the gist I created for the article to talk about software programmer interview and computer science PH.D. program.

A few arguments to think about 

Here are some good arguments to think about from the above article.

Argument 1:

很早之前在B家工作时,就与同事们有一个传统,就是保持市场竞争力的最好方式是出公司面试,看看自己的技能和经验在市场中的价值, 以此判断自己在行业中的位置,是被淘汰还是引领。所以,面试硅谷并不仅仅是为了执行自己的决定,也是一种校正职业方向的方式。

Tennis sports and friendship

June 22, 2018


I make a new friend so quickly before I even notice. Last time I went to the tennis court to hit against the wall, the young man next to me told me that he played tennis with me before last year, I have no clue maybe he lied. So I asked him to rally with me on tennis court since I like to run more on the court.

I learn to respect the partner time and also give feedback nicely. I asked him to put more topspin and therefore he can place the tennis ball just before me, one meter away, not running too hard, and show him to put more windshield wipe on the swing. Sometimes I just coach those friends to quickly be my professional hitting partner. He came to the court multiple times a day in the weekend, I told him that I could not come the morning and afternoon because I need to work at home. I need to have 30 minutes workout, run a lot hitting on tennis court.

Old friends also start to like me since I share the tips and show up on tennis courts more often. I am open to stay alone and hit against the wall at the beginning, hunting for hitting partner for next 20 to 30 minutes.

I still remember one advice from the senior player, he told me once there are 12 courts, every five minutes there is change on one of courts. I am just very patient. This can apply to those job seekers on software engineer area as well.

I have done a lot of study on tennis sports, so when a friend told me that she fell on the tennis court, and her partner also fell a few times. He showed me how he fell when he walked backward. I took a few minutes to explain how to run backward using correct foot work [Ref. 1] to prevent falling, expand the center of body weight in-between two legs widely separated.

Today I went to court and started to play against the wall. I was invited to play a double match. I believe that last time I shared the safety tip, they like my advise. After the match, I start to rally against another player.


I think about those friendship on tennis court. I play tennis with a lot of people, some of them put a lot of hours on tennis court this season. I need to work on algorithm and contest, I usually cut time to maximum two hours every time. I only show up a few times a week.

We used to spend hundreds of hours together last few years. I cannot spend hundreds of hours on tennis court this summer.

Summer is such great time in the city of Burnaby central park. I need to lose more weight and need to get those friends help me to stay on the court, play harder and run for each tennis ball.

Editorial note:

What happen to those colored sentence?
I wrote the blog first. And then I read again in the second day, I like to make correction. I added some content to make the blog more meaningful. So I highlighted those additional clauses.



Friday, June 22, 2018

week of code 38

June 22, 2018


It is time for me to work on week of code contest again. I miss those medium level algorithm and those long hours to work on algorithm and try to advance the ranking. I like to dedicate at least more than 8 hours on the contest.

Life can not be that hard. As long as I try to solve hard and advanced level algorithm every week, I will learn something and also fully enjoy the time to work on those algorithms.

Thursday, June 21, 2018

Day five - hard level algorithms

June 25, 2018

It is time for me to read hard level problems 10 algorithms a time. I just could not believe that I will read the problems first, and come back any time if I like to think about more how to solve them.

668 40.7%Hard
675 26.9%Hard
24 Game    
K Empty Slots    
685 27.6%Hard
689 41.4%Hard
691 35.1%Hard
699 38.1%Hard
711 41.9%Hard
Range Module    

Day four - hard level algorithms

June 25, 2018

It is time for me to read hard level problems 10 algorithms a time. I just could not believe that I will read the problems first, and come back any time if I like to think about more how to solve them.

Max Stack    
719 27.7%Hard
726 43.4%Hard
727 31.2%Hard
730 35.4%Hard
732 49.6%Hard
736 41.9%Hard
Cherry Pickup    
745 26.0%Hard
Contain Virus