【中国经营者】孙洁 携程新挑战

Here is the video.

携程没有对手？业内：已到最危险时候 住宿业务已被超

Here is the article.

Ctrip wants to expand its share of the Chinese travel market

Here is the article.

How One China Power Couple Balances Work And Home Life

Here is the link.

Global Tech Forum 2018: AI and the Future of Travel I Fortune

Here is the interview's link.

Ctrip has 8000 engineers to work for the company.

Ctrip CEO Jane Sun: ‘my career is a reflection of China’s 40 years of development and opening up’

Here is the article I like to read. I like to figure out if I should purchase Ctrip stock since the stock is not in highest price right now. I like to own Ctrip since I use the service all the time when I travel back to China last 10 years.

Best of Bloomberg Technology - Week of 11/01/19

Here is the link.

Some food stocks falling today as broader market rallies

Here is the link.

October saw markets hit all-time highs, is this a rally you should fear?

Here is the link.

2019 review: how is my job performance?

Nov. 3, 2019

Introduction

It is my 10th year on the same job. I like to look into job performance as a research topic, how can I learn to improve my performance and also I do enjoy learning a lot of things at work as well.

My job performance

I quickly looked up all check stubs paper copy at my home office. Here is the list of bonus history.

2010   No bonus
2011   No bonus
2012   No bonus
2013   No bonus
2014   Yes! I got bonus
2015 
2016
2017
2018
2019

2019 review: motivations to blog

2019 review: my favorite blogs - top 10

2019 review: privacy concern

2019 review: blogging and make money

Introduction

It is my favorite topics, one is about blogging, second one is about making money. I just could not believe that I have to relearn equity investment after 20 years, 53 year old. I like to write about the experience.

Blogging is a good habit

I started to write blogs for myself in January 2015, and then in 2019 March, I found out that I need to go back to equity market. I spent months to study myself as a consumer and an investor, I was heavily biased and lack of education of financial market.

Here is the link to look up all blogs related to my 401 K experience. I am a hard working person, but I do not know that the most important is to learn how to manage my asset and take some risk last 20 year from 1999 to 2019.

I did go back to equity market, and then set up my USA IRA portfolio Key Largo six months ago, and also set up Canada dollars portfolio using TFSA account. Although I do not have a lot of money, I like to demonstrate the belief starting from a seed a tree will grow.

2019 review: work on feedback

2019 review: a few rules to follow when practice

2019 review: why I prefer not to write code sometimes?

2019 review: when to write code?

Introduction

It is the habit for me to write code once a week at least. Sometimes I just like to warm up my problem solving skills, so I spend a few hours to study, read some algorithms, and then try out using C#. I know that my life is so simple in 2019. I choose to have a simple life, work on personal finance research, and then from March to August, I was busy with Amazon, Microsoft code screen, online assessment, mock interview on interviewing.io, and then onsite interview preparation, system design study.

When to code

I do believe that it is important for me to learn system design. But I know that if every one can learn system design, what is good about me doing it. I have to push myself to work on my crafting skills. I like to work on algorithm and data structure, go through easy level algorithms first, and then write code. I played weekly contest as well from January to July almost every week.

Sometimes I have some issues related to time management. I do not notice and then I do not have time reserved for coding. I prefer to code in weekends or evening, but I notice that I have to spend time in weekends to go out, play sports and other activities. Evening is good time but I should not stay late passing midnight, it is not healthy.

One algorithm a time

I also like to push myself work on one algorithm a time. Do not just write C# code. I should write JavaScript code as well, I was a good Javascript programmer. I should learn to write using Python as well.

Do not just write C# code for an algorithm. Write a post to share on leetcode.com as well. Stay organized, put all practice in record.

2019 review: do I write enough code?

Introduction

It is the first day in November. I like to review how many code I write in C#, JavaScript, html and CSS code. I like to see if the quality of my work matters more compared to the amount of code I write.

Github history

I can quickly look up how many codes I check in on github in 2019 for my full time job. I am the only developer as a full stack programmer. I did not write a lot of code at all. Most of time, I will take some time to warm up CSS, html and JavaScript, C#, and then I will write some code less than a few days for a feature update. 

10 years experience

I think that I am a very competitive programmer in terms of writing applications, like web page, or I learn something related to web technology. I can just quickly go over the technology, and then go over some sample code, and then I can quickly come out the guess how many hours work I should spend to complete the project.

Focus on training

I also need to work on a lot of things related to website maintenance, understand the code I wrote before. I do not need to write code in order to support the business, and I can move the business logic to high organized manner, like JavaScript array, a table in the database, so I do not need to write code.

Sometimes I cannot remember the logic I put together, I need to debug the code and then figure out the design; sometimes it takes some time to change the code and test the code to make it more efficient. But I try to evaluate whole project, do not focus on too much detail one a small section.

As a programmer, I like to see how I can maintain high quality service using website to serve other business needs.

Leetcode training

In 2009, I practice over hundred Leetcode algorithms.

Nov. 20, 2018  320
March 26       371
April 24       392
Oct. 17        433
Nov. 11        451

Here is Leetcode source code folder. I checked in 70 C# files in 2019.

Case study: my mock interview as an interviewee on Oct. 31, 2019

Oct. 31, 2019

Introduction

I had a mock interview today at 10:00 PM, and I like to write case study of my mock interview. It is important for me to learn how to pass mock interview on interviewing.io.

Case study

The code I wrote for the first algorithm.
Extended algorithm

Interviewer feedback

Actionable Items

Follow up
Nov. 2, 2019

My ranking of interviewer does not match the feedback I wrote about the interviewer. I should lower the ranking of interviewer, at most 3. I have to learn how to make decision based on my careful consideration first.

Do not give the interviewer rank 4, which should be 2, not as good as 3.

Case study: mock interview August 5, 2019 interviewee Serial Lambda

Oct. 31, 2019

Introduction

It is such a good interview and I like to work on a case study on this mock interview. I like the interviewer and how he gave out hints, and the communication between two engineers. The mock interview is on August 5, 2019 Serial Lambda - interviewee.

Case study

The algorithms asked in the interview are Leetcode 941, and Leetcode 1055.

I really like the learning experience to watch the interview. I also like the algorithm since I could not figure out the algorithm at the beginning without his hint.

It is a good idea to preprocess the source string into a hashmap first.

475. Heaters

Here is the link.

C# binary search to avoid timeout issue

It is an easy level algorithm, so I wrote the brute force solution first, and then I came cross timeout issue. I learn to write a binary search algorithm to expedite the process to find minimum value.

To understand C# Array.BinarySearch, it is also necessary to understand return index with negative value of BinarySearch API.

Time complexity: maximum of values {nlogn, mlogm, nlogm}, n is length of houses, m is length of heaters

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _475_heaters___binary_search
{
    class Program
    {
        static void Main(string[] args)
        {
            var result = FindRadius(new int[]{1, 2, 3}, new int[]{2}); 
        }

        /// <summary>
        /// 475 heaters
        /// binary search review 
        /// https://docs.microsoft.com/en-us/dotnet/api/system.array.binarysearch?view=netframework-4.8
        /// If the Array does not contain the specified value, the method returns a negative integer. 
        /// You can apply the bitwise complement operator (~ in C#, Not in Visual Basic) to the 
        /// negative result to produce an index. If this index is one greater than the upper bound 
        /// of the array, there are no elements larger than value in the array. Otherwise, it is 
        /// the index of the first element that is larger than value.
        /// 
        /// Time complexity: maximum of values {nlogn, mlogm, nlogm}, n is length of houses, m is length of heaters
        /// </summary>
        /// <param name="houses"></param>
        /// <param name="heaters"></param>
        /// <returns></returns>
        public static int FindRadius(int[] houses, int[] heaters)
        {
            if (houses == null || houses.Length == 0 ||
                heaters == null || heaters.Length == 0)
            {
                return 0;
            }

            var minumumRadius = Int32.MinValue;

            Array.Sort(houses);
            Array.Sort(heaters); 

            foreach (var item in houses)
            {
                // For each house, find minimum distance to one of heaters
                var minimumValue = Int32.MaxValue;

                var index = Array.BinarySearch(heaters, item);

                var length = heaters.Length;

                if (index >= 0)  /* should be >=, not > - caught by online judge */
                {
                    minimumValue = 0;
                }
                else
                {
                    var firstLarger = ~index; /* ~ complement operator */
                    if (firstLarger >= heaters.Length)
                    {
                        minimumValue = Math.Abs(item - heaters[length - 1]);
                    }
                    else
                    {
                        minimumValue = Math.Abs(item - heaters[firstLarger]);
                        if (firstLarger - 1 >= 0)
                        {
                            minimumValue = Math.Min(Math.Abs(item - heaters[firstLarger - 1]), minimumValue); 
                        }                       
                    }
                }

                // From all houses, choose maximum one from the distance to heater.
                if (minimumValue > minumumRadius)
                {
                    minumumRadius = minimumValue;
                }
            }

            return minumumRadius;
        }
    }
}

Two hours fitness training every day

Oct. 31, 2019

Introduction

It is my bias to try to hide my age, and things I have to learn to deal with 53 years old brain and physical strength. I wish that I can spend one or two hours every day to play sports, warm up every big muscle, and do a lot of conditioning training to keep myself fit and also stay in good shape.

Two hours fitness training

I like to figure out how I can do two hours fitness training every day.

Personality weakness

Oct. 30, 2019

Introduction

It is my short research. I like to figure out how to be a good interviewer on interviewing.io, so I decide to study all show case interviews.

My weakness

I have some weakness as an interviewer. I need to learn how to give interviewee full spectrum of scores, 1 to 4.  I was scared to give people low rating since I thought I may hurt people's feelings.

530. Minimum Absolute Difference in BST

Here is the link.

C# Inorder traversal solution

Oct. 30, 2019
To traverse the binary search tree in ascending order, inorder traversal is chosen. Inorder traversal is to visit left node, root node and then right node. The previous node is declared as static variable, to work with more than one test cases, it is important to reset previous node to null.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _530_minimum_difference_in_BST
{
    class Program
    {
        public class TreeNode {
            public int val;
            public TreeNode left;
            public TreeNode right;
            public TreeNode(int x) { val = x; }
        }

        static void Main(string[] args)
        {
            var node1 = new TreeNode(1);
            var node5 = new TreeNode(5);
            var node3 = new TreeNode(3);

            node1.right = node5;
            node5.left = node3;

            var result = GetMinimumDifference(node1); 
        }

        static TreeNode previous;
        /// <summary>
        /// 
        /// </summary>
        /// <param name="root"></param>
        /// <returns></returns>
        public static int GetMinimumDifference(TreeNode root)
        {
            previous = null;  // caught by online judge - Oct. 30, 2019
            int minDiff = Int32.MaxValue;
            traverseInorder(root, ref minDiff);
            return minDiff;
        }

        /// Left, Root, right
        private static void traverseInorder(TreeNode root, ref int minDiff)
        {
            if (root == null)
                return;
            traverseInorder(root.left, ref minDiff);

            // handle root node
            if (previous != null)
            {
                var current = root.val - previous.val;
                minDiff = current < minDiff ? current : minDiff;
            }

            previous = root;

            traverseInorder(root.right, ref minDiff);
        }
    }
}

8 tree algorithms to practice

Oct. 30, 2019

Introduction

It is my most favorite job in the world to solve tree algorithms. There are 6 medium level tree algorithms and 2 hard level algorithms available for me to solve. I am so excited and look forward to best learning experience in short future.

Tree algorithms

Here are those tree algorithms I like to solve.

Hard level, 968, 1028
Medium level, 117, 116, 1145, 1130, 1123, 1104

5 Ways The Rich Build Wealth That The Poor Don't | How To Get Rich From Nothing

Here is the link.

Studio 1.0: Mark Zuckerberg

Here is the link.

Interviewing.io showcase study

Oct. 30, 2019

Introduction

It is time of year I like to search good ideas, and I like to find time to solve more easy level algorithms or medium level on Leetcode.com next two months. One of ideas is to study time to review all showcases on interviewing.io. I like to learn from other interviewers and interviewees.

Showcases

I like to write down some notes about my study. I like to take time to watch, and also try to evaluate how good interviewers are.

450 mark - I just solved 450 Leetcode algorithms

Oct. 30, 2019

Introduction

I just spent less than 30 minutes to solve one easy level tree algorithm, so I just reached 450 mark. In other words, I just solved 450 algorithms on leetcode.com. Unbelievable.

My 450 mark

Here is the algorithm I just solved which is an easy level tree algorithm. I solved 9 easy level algorithms tagged with array last week. I learned to write easy ones in order to push myself with busy schedule - a full time job.

I just like to showoff my mark - 450 solved algorithm.

It is such a bargain, in order to solve more algorithms, I choose to solve easy level ones first. I do believe that I can learn much better through easy level ones.

Facebook Hackathon; Mark Zuckerberg showing what his team has built

Here is the link.

14 SUREFIRE WAYS TO IMPROVE YOUR FINANCES IN 2020

Here is the article.

12. EDUCATE YOURSELF

An investment in knowledge pays the best interest. – Benjamin Franklin

Increase your knowledge and improve your skills by continuously reading and learning. Investing in yourself is one of the most important investments you will ever make. Through education, you may be able to: increase your income-earning ability, increase your capacity to provide solutions to real-life problems, broaden your general understanding and thinking ability, and feel fulfilled and satisfied with your life.

In the area of finances, there are many personal finance books you can read this year to increase your understanding of investing, debt management, budgeting, and more, including:

The Automatic Millionaire by David Bach: This is a clear guide on how to build wealth and financial freedom on any income.

I will Teach You How To Be Rich by Ramit Sethi: A six-week program that shows millennials (20- to 35-year olds) how to master their money easily.

The Total Money Makeover by Dave Ramsey: This book shows you how to beat crushing debt!

The Little Book of Common Sense Investing by John Bogle: Written by the father of index investing, the book gives you insight into how simplified investing pays best.

The Richest Man in Babylon by George Clason: See how ancient financial truths still hold sway in today’s world.

【Netflix 纪录片 双语字幕可选 】走进比尔：解码 比尔·盖茨 2

Here is the link.

NVIDIA Shares Are Surging With Huge Demand

Here is the article.

A gain of 53.07% in 2019 for shares of NVIDIA Corporation (NVDA) tells a story of big buy demand lifting the shares. This buying is very unusual and has been happening very recently. As the move to 5G ramps up, some semiconductor stocks could be rewarded handsomely. We think the rush for this group is happening now. A great way to uncover tomorrow's winners is to look for great stocks seeing big buy activity, and NVIDIA could be just the opportunity.

I wish that I learn that NVIDIA stock is the good choice to purchase.

53.07%
53.07%
53.07%
53.07%
53.07%

Why Your Realistic Goals Are Holding You Back

Here is the link.

How to Radically Change Your Goals and Success

Here is the article.

Are you living 10X?

"Being careful requires you to take actions cautiously--and there is no way that you will ever hit 10X activity levels by being cautious." ― Grant Cardone

Look at your goals for 2016. Chances are, they reflect timid thinking and less-than-creative planning. Without question, your goals are less challenging than you can handle. You are more than you know. You can handle more than you think. You can adapt to anything.

As an example, if your goal is to earn $50,000 in 2016, I challenge you to change that goal to $500,000.

When you 10X your goals, you will be forced to approach your goal in non-conventional and innovative ways. The traditional approach doesn't work with 10X thinking.

Not only does your mind need to expand in what you plan and strive for, but your daily effort needs to change as well. Just as people underestimate their personal ability, they also underestimate how much effort and time something will take. Thus, people are frequently late for appointments and fail to complete projects they begin.

Rather than expecting ideal circumstances, plan for the worst. Rather than underestimating how much time and effort something will take, over estimate those things. Put way more effort into your goal than you think is required to get there.

If you're going to think 10X, you have to also put in 10X effort. Without the effort, it doesn't matter how "big" your dreams are. But once your behavior matches (and exceeds) your intentions, your dreams quickly become a reality.

The 10X Rule by Grant Cardone

Here is the summary.

• Limiting the amount of success you desire is a violation of the 10X Rule.
• The 10X Rule: You must set targets for yourself that are 10X more than what you think you want and then take 10X the action you think is required to get there.
• Common mistake 1: setting your sights too low.
• Common mistake 2: underestimating how much action is required.
• Common mistake 3: spending too much time competing and not enough time dominating their sector.
• Common mistake 4: underestimating the amount of adversity they will have to overcome.
• Any goal you set is going to be difficult to achieve, so why not set them higher from the beginning?
• Most people feel like they are working – rather than chasing passion – because the payoff isn't large enough.
• You will either work to accomplish your goals and dreams or you'll be used to accomplish someone else's goals and dreams.
• Never reduce a target. Do not explain away failure. Always increase your actions.

10 x high goals

Oct. 29, 2019

Introduction

It is my personal finance research. I did review those videos about the book 10 X rule. I like to figure out how to apply the idea to my personal situation.

1239. Maximum Length of a Concatenated String with Unique Characters

Here is the link.

C# A solution with readable code using DFS

It is the algorithm which can be solved using depth first search. I like to practice and also make the code easy to write and readable.

Here are highlights:

1. Design depth first search and recursive function with four arguments;
2. default empty string is considered as a unique string with my defined isUnique function;
3. Depth first search algorithm is to go through all possible paths starting from a list from 0 to length - 1;
4. isUnique function is implemented to compare a hashSet's count to string's length.

Follow up
I did not come out the solution in weekly contest 160 on Oct. 26, 2019. It is a simple brute force DFS solution. I will look into how to improve performance on weekly contest.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _1239_maximujm_length
{
    class Program
    {
        static void Main(string[] args)
        {
        }

        /// <summary>
        /// Oct. 29, 2019
        /// study code
        /// 1239 Maximum length of concatenated string with unique characters
        /// My ideal solution is to write a DFS solution which can easily be understandable, 
        /// and also it can be written in less than 15 minutes. 
        /// </summary>
        /// <param name="arr"></param>
        /// <returns></returns>
        public int MaxLength(IList<string> arr)
        {
            var maxLength = 0;

            runDFS(arr, ref maxLength, 0, "");

            return maxLength; 
        }

        private static void runDFS(IList<string> array, ref int maxLength, int index, string path)
        {
            if (!isUnique(path))
            {
                return;
            }

            var current = path.Length;
            maxLength = current > maxLength ? current : maxLength;

            for (int i = index; i < array.Count; i++)
            {
                runDFS(array, ref maxLength, i + 1, path + array[i]);
            }
        }

        private static bool isUnique(string path)
        {
            var hashSet = new HashSet<char>(path);
            return path.Length == hashSet.Count(); 
        }
    }
}

989. Add to Array-Form of Integer

Here is the link.

Oct. 29, 2019

It is hard to write an iterative solution first time without a bug. I choose to study one of iterative solution, but I do think that it is better for me to add an extra variable called sum, and then work on its calculation.

The code is written in the following:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _989_Add_To_Array_Form_III
{
    class Program
    {
        static void Main(string[] args)
        {
        }

        /// <summary>
        /// 989. Add to Array-Form of Integer
        /// iterative solution
        /// study code
        /// https://leetcode.com/problems/add-to-array-form-of-integer/discuss/234521/C
        /// </summary>
        /// <param name="words"></param>
        /// <param name="chars"></param>
        /// <returns></returns>
        public IList<int> AddToArrayForm(int[] A, int K)
        {
            var length = A.Length;

            var result = new List<int>();

            int index = length - 1;
            while (index >= 0 || K > 0)
            {
                var sum = K % 10;
                sum += (index >= 0 ? A[index] : 0);

                if (sum >= 10)
                {
                    K += 10; 
                }
                
                index--;

                result.Add(sum % 10);
                K /= 10;
            }

            result.Reverse();
            return result;
        }
    }
}

989. Add to Array-Form of Integer

Here is the link.

Oct. 29, 2019

Here are highlights of my practice:

1. Work on recursive solution. Figure out base cases
2. Work on rightmost digit in K first, and try to do some basic work for the algorithm. Make sure that it is minimum.
3. It is the first time I learn to write IEnumerable.Take, and look into how to use IEnumerable.Skip.

Extra sharing of my training thought process

It is my idea to be humble and work on easy level algorithm first. I solved all easy level algorithm (220 easy level algorithm solved) in Dec. 2018. Now there are around 60 new easy level algorithms available released after Dec. 2018, I like to work on those algorithm first, and I chose to work on 9 easy level array algorithms first, continue to work on rest of easy level ones.

I believe that easy level algorithms are better to train myself compared to those medium level ones.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _989_Add_To_Array_Form
{
    class Program
    {
        static void Main(string[] args)
        {
            var result = AddToArrayForm(new int[]{1, 2, 3, 4}, 34); 
        }

        /// <summary>
        /// Oct 29, 2019
        /// Leetcode 989 Add to array form
        /// recursive solution 
        /// First time I learn to use IEnumberable.Skip and IEnumberable.Take
        /// </summary>
        /// <param name="A"></param>
        /// <param name="K"></param>
        /// <returns></returns>
        public static IList<int> AddToArrayForm(int[] A, int K) 
        {
            if(K == 0)
            {
                return A.ToList(); 
            }
        
            if(A.Length == 0 && K < 10)
            {
                return new int[]{K}.ToList();
            }
        
            var rightmost = K % 10; 
            var rest = K/10; 
            var sum = 0; 
            if(A.Length == 0)
            {
                sum = rightmost;
            }
            else 
            {
                sum = A[A.Length - 1] + rightmost;
            }
        
            var lessThan10 = sum < 10; 
        
            // recursive solution 
            IList<int> list =  new List<int>();
            var value = rest + (lessThan10 ? 0 : 1);
            var aLength = A.Length;

            if (aLength == 0)
            {
                list = AddToArrayForm(new int[0], value);
            }
            else
            {
                list = AddToArrayForm(A.Take(aLength -1).ToArray(), value);
            }

            list.Add(sum % 10);

            return list;                    
        }
    }
}