Month: November 2021

Block Storage vs. File Storage – Part 1

In this post we will not be solving a problem yet. This post is about code I wrote to experiment with differences between file and block storage.

In this post we will start by writing some data into individual files. This will set the ground for some differences that arise when you access similar data in block mode possibly in a cloud storage setting.

This code has been written in C on a Windows platform. For my benefit regarding ease of development, I have used some previous code found in a set of libraries which at this point I am not allowed to disclose. That said; when we encounter such calls I will suggest ways you can replace them with much simpler code. Sorry for the inconvenience this may cause. Continue reading “Block Storage vs. File Storage – Part 1”

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”

Find Leaf Nodes in a Tree for which the Sum of the Root Path Matches a Target Value

I did not find this problem on a website. The requirements came up during a conversation with a software engineer. I wish I could have taken some notes but I did not. The problem had a single diagram of a sample general tree and there was no class definition for the nodes.

We are given a general binary three in which a node may have none, one or more children.
In addition each node has an integer value.
The values may repeat.

Our tasks if to come up with a function 
that will display the leaf nodes 
for which the sum of all node values in the path from the root 
add up to a defined target.

As far as I can remember that was the gist of the problem. Continue reading “Find Leaf Nodes in a Tree for which the Sum of the Root Path Matches a Target Value”

Brackets

Good day! In this post we will attempt to solve the Brackets problem from Codility_.

A string S consisting of N characters is considered to be properly nested if any of the following conditions is true:

o S is empty;
o S has the form "(U)" or "[U]" or "{U}" where U is a properly nested string;
o S has the form "VW" where V and W are properly nested strings.

For example, the string "{[()()]}" is properly nested but "([)()]" is not.

Write a function such that given a string S consisting of N characters, 
returns 1 if S is properly nested and 0 otherwise.

Write an efficient algorithm for the following assumptions:

o N is an integer within the range [0..200,000];
o string S consists only of the following characters: "(", "{", "[", "]", "}" and/or ")".

We are presented with a string. We need to determine if the different types of brackets match. If interested in this problem I suggest you read the current and full description at Codility_. Continue reading “Brackets”

Sum of Nodes Between Two Nodes in Binary Tree

Good day!!! Hope all is going well for you. It is Friday and has been a very stressful week for me. Glad that the weekend is just around the corner.

Today we are going to cover a problem which a software engineer and I discussed earlier this week, but for some reason or the other, we did not generate code at the time. We just talked about it.

We are given a binary tree with integer values and two different nodes in the binary tree,
we must return the sum of the values of the nodes that connect p and q inclusive.

Constraints:

o -1000 <= val <= 1000
o 2 <= n <= 200

As you can see, we are given a binary tree populated with integers. Do not recall if all integers were included. We will assume, since I am writing the requirements as we speak, that the values for the nodes are in the specified range and the number of nodes in the binary tree should not exceed the specified value. Continue reading “Sum of Nodes Between Two Nodes in Binary Tree”

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”

Slow Sum – Revisited

Good morning. I received a comment from Dmytro regarding the post Slow Sum suggesting the use of a priority queue instead of a stream. I appreciate the comment and suggestion. Continue reading “Slow Sum – Revisited”

MaxProductOfThree

Good morning! Hope your day has started on the right note.

In this post we will attempt to solve the Codility_ problem MaxProductOfThree using the Java programming language and the VSCode IDE on a Windows platform. We will not be using the online IDE provided by Codility_ since we will write the code on a separate computer. Continue reading “MaxProductOfThree”

Binary Gap

Happy Monday! It is another cold fall day in the Twin Cities of Minneapolis and St. Paul. In the past few days I have been solving a few problems from the Developer Training section in the Codility_ website. As I have mentioned several times, it takes time to write these posts. I usually do not solve more than one problem a day. I am doing so and will continue until I complete all the problems posted in the Codility_ Developer Training Lessons section. So in order to save some precious time, I will be limiting my chit-chat to a sentence or two.

I am also starting to look at tools and equipment to start my YouTube channel. Planning on getting my first post early in January 2022. Will see how that goes. Continue reading “Binary Gap”