@rkenmi - Search Results

P vs. NP

P vs. NP is a millenium-prize problem in Computer Science that has not been proven yet. Are all P in NP? Or are all NP in P? What is NP-Complete? P vs. NP When we talk about P or NP, we generally talk about decision problems, which means the algorithms always output a "yes" or a "no".

October 11, 2017

Math Formulas for C.S.

Sum of the first $n$ integers $1 + 2 + 3 + ... + n = $ $$\sum_{k=1}^n k = \frac{1}{2}n(n+1)$$ Use cases: Finding a missing number from $1 ... n$ Sum of the squares of the first $n$ integers \(1^2 + 2^2 + 3^2 + .

May 27, 2019

Misconceptions of ASCII and Unicode

Myth: ASCII characters take up one byte ASCII represented characters using numbers between 32 and 127. This accounted for characters used in the English language (lowercase and uppercase) and the numbers between 1-32 were reserved control characters.

May 29, 2022

Stack Memory vs. Heap Memory

Stack Memory The stack memory is used within a context of a thread. It is called stack memory since memory blocks are allocated in LIFO order, based on the function call stack. Each stack memory block houses data for local variables, references, and other bookkeeping data.

May 28, 2019

Build a Trie in Python

Problem In computer science, a trie (pronounced "try"), also called digital tree, radix tree or prefix tree, is a kind of search tree—an ordered tree data structure used to store a dynamic set or associative array where the keys are usually strings.

February 3, 2019

Misconceptions of Software Engineer interviews at FAANG

There are already so many articles and Quora/Reddit/Blind posts out there on how to interview prep to get into big companies. So instead of covering that in detail, I want to focus more on the angle of common misconceptions.

August 15, 2020

Scanning for memory addresses with Cheat Engine and ZSNES

Cheat Engine (CE) is an open source memory scanner/hex editor/debugger that works for Windows applications. Another way to put it is that CE is used to explore the memory that is dynamically allocated (by Windows) in games.

July 4, 2017

Composite Pattern

The Composition design pattern helps you unify individual objects and nested objects. Here is one use case for the composition design pattern. Meet Frank A man named F. Frank decides to write an autobiography of himself.

May 15, 2017

DataFrames (a software engineer's perspective)

What is a DataFrame? A DataFrame is a special data structure used primarily by data scientists and machine learning algorithms. It contains row and column data in tabular fashion by storing metadata about each column and row.

May 2, 2022