LeetCode 75. Sort Colors in Java

In this post we will solve the LeetCode 75. Sort Colors problem using the Java programming language and the VSCode IDE on a Windows computer.

Given an array nums with n objects colored red, white, or blue, 
sort them in-place so that objects of the same color are adjacent, 
with the colors in the order red, white, and blue.

We will use the integers 0, 1, and 2 to represent the color red, white, and blue, respectively.

You must solve this problem without using the library's sort function.


o n == nums.length
o 1 <= n <= 300
o nums[i] is 0, 1, or 2.

We are given an integer array with values 0, 1, and 2 which represent colors red, white and blue respectively. We must solve the problem without the use of any library sort function. That makes sense because we would only have to sort the input array and return. Continue reading “LeetCode 75. Sort Colors in Java”

LeetCode 229. Majority Element II in Java

In this post we will solve the LeetCode 229. Majority Element II problem using two approaches.

Given an integer array of size n, find all elements that appear more than floor(n/3)times.


o 1 <= nums.length <= 5 * 10^4
o -10^9 <= nums[i] <= 10^9

We are given an array of integer values. We need to find all elements whose values are larger than floor(n / 3), where `n` is the number of elements in the input array. Continue reading “LeetCode 229. Majority Element II in Java”

Codility_ problem Fish in Java

In this post we will attempt to solve the Codility_ problem Fish (https://app.codility.com/programmers/lessons/7-stacks_and_queues/fish/) in which we are given N voracious fish are moving along a river. Calculate how many fish are alive. Continue reading “Codility_ problem Fish in Java”

Stone Wall

Good day! Hope all is well in your neck of the woods. My wife left lunch in the oven and ran to the dentist office. She left the oven on. Not sure when I should shut it down. I think I will do it right now before the food gets burned. When she gets back we can turn on the oven back if needed.

OK, the oven is off. It is 01:00 PM. I am starving. Hope my wife returns shortly so we can have lunch. Continue reading “Stone Wall”

Middle of the Linked List

I am working on the last 2-hour block of the day. My wife was trying to make a payment for our Internet service, but she needs a number that can only be found in a previous bill receipt. Apparently she can not find one, so at the end of the workday we will go to make a payment in person and will hopefully keep the receipt, so this situation does not repeat. Continue reading “Middle of the Linked List”

Reverse Words in a String III

Good day! Hope your day has started on the right note. Earlier today I participated in a video call using Zoom. I have avoided using Zoom due to security issues. Today I had to install it in order to participate in the call. It seems that the look and feel has improved considerably. Will read more about security issues in the past few months. One way or the other, after the call ended, I removed the application from my Windows computer.

I was chatting with a software engineer and the idea of replacing the garbage collector in Java came up. In general you would replace it if it is not keeping up with the task (i.e., too many requests when processing IoT calls). I am aware and have done it using C and C++. After completing this post I will spend an hour researching more on this subject. Continue reading “Reverse Words in a String III”

Two Sum II

Good morning. Hope you enjoyed the Halloween festivities yesterday. Today is November 01, 2021 and most countries celebrate today “All Saints’ Day” and tomorrow “All Souls’ Day. In the USA we do not celebrate these holidays.

One way or the other, yesterday shortly past noon the crew of technicians installing our new furnace left, leaving us with an installed, calibrated, and properly functioning furnace. Last night  the low temperature in this part of the Twin Cities of Minneapolis and St. Paul was 30F. The furnace worked a few times at night. It was quieter than our previous unit. What is more important, it worked flawlessly.

Today I have a couple meetings. Besides that it will be a normal workday.

Continue reading “Two Sum II”

Best Time to Buy and Sell Stock II

It is a relatively nice day in the Twin Cities of Minneapolis and St. Paul.

This weekend my wife and I will go to visit our younger son. His house is about three hours by car. It does not make sense to fly. It will take longer than driving when you consider the overhead at the airports.

I continue giving it a try to the process to solve dynamic problems using some simple steps as described in the paper Dynamic programming is simple by omgitspavel. Each time I give it a try I add additional guidance.

The main problem that I see with the approach is that one still has to read, understand and explore other methods before diving into dynamic programming. The problem we will be solving in this post can be resolved faster and better not using dynamic programming. Continue reading “Best Time to Buy and Sell Stock II”

Divide Chocolate

Good day! Hope your workday has started on the right note. Currently in the USA we are observing the Daylight saving time which this year ends on Sunday, November 7, 2021. Today is Thursday October 14, 2021 so we have a little over one month for the time to get back to normal.

I see the positive sides of daylight savings time during summer. In my opinion, in the USA, daylight savings should start on Memorial Day and end on Labor Day. The reason for this is that schools and universities tend to be off during such period.

For college students it should not make much of a difference, but for K-12 students it does. Most children use public school buses to commute to school. Depending on the grade they attend, they may be picked up in the morning around 07:00 AM. I am always up before 06:00 AM. I am a morning person. After fixing breakfast I wake up my wife so we can have the first meal of the day together.

After we are done with breakfast, she helps me with the dishes. After rinsing the dishes and putting them in the dishwasher I shower, get dressed, and head down to my office to work on my first 2-hour block of the day. This includes weekends in which I work one or at most two blocks. On regular workdays I tend to do four to five blocks a day.

For the past week or two, when I head down to my office, the day is very dark, to the point that I have to turn on lights. It happens that when I am heading down is about 07:00 AM and I see kids that are already riding public school busses. They had to walk from home to the bus stop while it is quite dark. I thought that children were first in our society. It seems I am wrong. Go figure!

In the month that we have to wait before daylight savings ends, it will be dark close to 08:00 AM. So why is this happening? Well, the thought is that if the school day ends with some light, parents will be more prone to head out and grab a bite which is good for business. I guess children do not have much homework in these days. Things have changed since I attended K-12. Continue reading “Divide Chocolate”