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Algorithms, Blockchain and Cloud
27  mars     15h19
Three Interesting Fun BASH Commands
ACMer    This post shows you interesting fun BASH commands: BASH Console Tetris Game You can now play tetris game in Bash console. You would need to install this via: sudo apt install bastet or sudo yum install bastet start the Tetris Game bastet Control the movement of Tetris blocks by the...
25  mars     10h11
Teaching Kids Programming - Reachable Nodes With Restrictions (Graph Theory, Union Find, Disjoint Set, Undirected Unweighted Graph)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms There is an undirected tree with n nodes labeled from to n and n edges. You are given a D integer array edges of length n where edges indicates that there is an edge between nodes ai and bi in the tree. You are...
22  mars     22h15
Teaching Kids Programming - Reachable Nodes With Restrictions (Graph Theory, Breadth First Search Algorithm, Undirected Unweighted Graph)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms There is an undirected tree with n nodes labeled from to n and n edges. You are given a D integer array edges of length n where edges indicates that there is an edge between nodes ai and bi in the tree. You are...
19  mars     14h55
Visiting The Raspberry Shop in Cambridge UK
ACMer    In the center of Cambridge, England, there is a Raspberry Pi store inside The Grand Arcade shopping center. This is one of only two offline Raspberry Pi stores in the UK official website , the other Raspberry Pi shop is in Leeds. The address of the Raspberry Pi store in Cambridge is: SU, The...
14  mars     14h54
Teaching Kids Programming - Reachable Nodes With Restrictions (Graph Theory, Recursive Depth First Search Algorithm, Undirected Unweighted Graph)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms There is an undirected tree with n nodes labeled from to n and n edges. You are given a D integer array edges of length n where edges indicates that there is an edge between nodes ai and bi in the tree. You are...
10  mars     18h26
Teaching Kids Programming - Least Number of Unique Integers after K Removals
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms Given an array of integers arr and an integer k. Find the least number of unique integers after removing exactly k elements. Example : Input: arr , k Output: Explanation: Remove the single, only is left. Example ...
09  mars     13h43
Teaching Kids Programming - Paint Fences (No 3 Consecutive Same Colours) - Bottom Up Dynamic Programming Algorithm
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms You are painting a fence of n posts with k different colors. You must paint the posts following these rules: Every post must be painted exactly one color. There cannot be three or more consecutive posts with the same color. Given...
06  mars     12h09
Teaching Kids Programming - Paint Fences (No 3 Consecutive Same Colours) - Top Down Dynamic Programming Algorithm (Recursion Memoization)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms You are painting a fence of n posts with k different colors. You must paint the posts following these rules: Every post must be painted exactly one color. There cannot be three or more consecutive posts with the same color. Given...
26  février     21h01
Teaching Kids Programming - N-Repeated Element in Size 2N Array (Pigeonhole Principle)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms You are given an integer array nums with the following properties: nums.length n. nums contains n unique elements. Exactly one element of nums is repeated n times. Return the element that is repeated n times. Example ...
18  février     22h42
Teaching Kids Programming - N-Repeated Element in Size 2N Array (Random Algorithm)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms You are given an integer array nums with the following properties: nums.length n. nums contains n unique elements. Exactly one element of nums is repeated n times. Return the element that is repeated n times. Example ...
14  février     11h15
Simple Bash Function to Repeat a Command N times with Retries
ACMer    Sometimes we want to repeat a command on Linux, and we can use the following BASH function to repeat a command for a number of times: function repeat COUNT if ; then COUNT fi for i in seq COUNT ; do echo Counter i: CMD if ; then echo Error i return fi done return ...
12  février     20h41
Teaching Kids Programming - N-Repeated Element in Size 2N Array (Math)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms You are given an integer array nums with the following properties: nums.length n. nums contains n unique elements. Exactly one element of nums is repeated n times. Return the element that is repeated n times. Example ...
10  février     16h38
Teaching Kids Programming - N-Repeated Element in Size 2N Array (Sorting)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms You are given an integer array nums with the following properties: nums.length n. nums contains n unique elements. Exactly one element of nums is repeated n times. Return the element that is repeated n times. Example ...
04  février     12h18
Teaching Kids Programming - N-Repeated Element in Size 2N Array (Hash Map Set)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms You are given an integer array nums with the following properties: nums.length n. nums contains n unique elements. Exactly one element of nums is repeated n times. Return the element that is repeated n times. Example ...
01  février     13h12
Teaching Kids Programming - Count Out of Boundary Path via Top Down Dynamic Programming Algorithm (Recursion with Memoization)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms There is an m x n grid with a ball. The ball is initially at the position . You are allowed to move the ball to one of the four adjacent cells in the grid possibly out of the grid crossing the grid boundary . You can apply at most...
30  janvier     14h51
Teaching Kids Programming - Remove Duplicates from Sorted Linked List (Using Hash Set)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms Given the head of a sorted linked list, delete all duplicates such that each element appears only once. Return the linked list sorted as well. Example : Input: head Output: Example : Input: head Output: Constraints: The...
27  janvier     10h11
Python Debugging: Get Current Executed Function Name and Print Traceback
ACMer    In Python, we can fail a test like this: def fail the test error msg : print error msg sys.stdout.flush sys.stdout.close this kills the process and make it return a non zero code os.kill os.getpid, signal.SIGKILL At this point, we can collect more information to help debugging. How to Get...
24  janvier     11h13
Teaching Kids Programming - Remove Duplicates from Sorted Linked List (Two Pointer Algorithm)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms Given the head of a sorted linked list, delete all duplicates such that each element appears only once. Return the linked list sorted as well. Example : Input: head Output: Example : Input: head Output: Constraints: The...
22  janvier     11h47
Implement a K-th Element for the Set in C
ACMer    A set in C aka std::set is a ordered set based on a Red Black tree while the unordered set is based on a Hash Map. Implement a K eth element for C Set in O K Implementing a function to find the k th element in a set in C can be done efficiently using iterators. A set in C is typically...
20  janvier     17h42
Teaching Kids Programming - Check if Bitwise OR Has Trailing Zeros (Binary)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms You are given an array of positive integers nums. You have to check if it is possible to select two or more elements in the array such that the bitwise OR of the selected elements has at least one trailing zero in its binary...
15  janvier     22h58
Teaching Kids Programming - Largest Substring Between Two Equal Characters (Brute Force, Find Index)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms Given a string s, return the length of the longest substring between two equal characters, excluding the two characters. If there is no such substring return . A substring is a contiguous sequence of characters within a string....
11  janvier     17h01
Teaching Kids Programming - Largest Substring Between Two Equal Characters (Hash Map)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms Given a string s, return the length of the longest substring between two equal characters, excluding the two characters. If there is no such substring return . A substring is a contiguous sequence of characters within a string....
07  janvier     18h21
Teaching Kids Programming - Linear Algebra: Using Matrix to Solve Equations of X and Y
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms Given the following two equations: We can work on the X or Y in one equation and then substitue it in another equation. For example: from Equation, we know and we can plug in x into the second equation. Linear Algebra: Using...
06  janvier     10h55
Teaching Kids Programming - Pseudo-Palindromic Paths in a Binary Tree (Breadth First Search Algorithm, Iterative Preorder Reversed Preorder)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms Given a binary tree where node values are digits from to . A path in the binary tree is said to be pseudo palindromic if at least one permutation of the node values in the path is a palindrome. Return the number of pseudo...
03  janvier     22h40
CloudFlare: Change Security Level Value Programmatically for Multiple Domains via PHP Python Bash Script
ACMer    I have domains, and they are all at CloudFlare. I would like to update the security level to all domains at once, programmatically. The security level could be one of these: Essentially off , low , medium , high and I’m under attack . Luckily, cloudflare provides API, and we can do this...
01  janvier     18h44
Teaching Kids Programming - Another Birthday Candles Problem (Binary Search and Brute Force Linear Search)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms Another Birthday Candles Problem Unlike the Original Birthday Candles Problem described here: Teaching Kids Programming The Birthday Candles Problem Three Algorithms , the number of candles blown for year N is the number of...
29  décembre     21h21
How to Transfer Domain From Namesilo to CloudFlare Registra?
ACMer    I have domains so far, and only currently managed by CloudFlare Registra. Recently I decide to migrate all domains to CloudFlare registra because of cost. At CloudFlare, it seems the cheapest fee to renew a .COM domain . per year while in Namesilo the fee is around . so domains...
    13h54
Adding Two Short Code Functions to WordPress: Top Posts By Number of Comments and Top Posts by Ratings
ACMer    The wordpress shortcode is a great feature that we can easily add via the add shortcode function. This post introduces two shortcode functions in WordPress to get the top posts by the comment count show top posts by comments or by the ratings show top posts by rating WordPress shortcode: Top...
27  décembre     14h52
How to Check Balances of a Bitcoin (BTC) Wallet Address via NodeJs or Python?
ACMer    Checking the Balances of a BTC bitcoin wallet address can be done in two ways: Querying a Node, or Querying a Third party API. Querying a Node requires running your own node, or some other existing nodes. Setting up a node could be complex and there is running cost incurred. Accessing some existing...
    12h18
Teaching Kids Programming - The Birthday Candles Problem (Three Algorithms)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms The Birthday Candles Problem If a person blows candle at Age, candles at Age, candles at Age, then what is the year of the birthday if he she has blown total candles. This can be solved using three algorithms...
22  décembre     12h37
Blog Traffic Declines after ChatGPT is Widely Adopted
ACMer    This blog traffic has declined a lot in the last days. The following shows the clicks from the Google Search in the Google Webmaster Dashboard. Take a look at the last months you will see the trend is declining very obviously. The peaks of the curve correspond to the mid week working days,...
21  décembre     15h40
Teaching Kids Programming - Pseudo-Palindromic Paths in a Binary Tree (Recursive Depth First Search Algorithm)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms Given a binary tree where node values are digits from to . A path in the binary tree is said to be pseudo palindromic if at least one permutation of the node values in the path is a palindrome. Return the number of pseudo...
18  décembre     16h24
Teaching Kids Programming - Count Unique Length-3 Palindromic Subsequences
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms Given a string s, return the number of unique palindromes of length three that are a subsequence of s. Note that even if there are multiple ways to obtain the same subsequence, it is still only counted once. A palindrome is a...
16  décembre     10h32
Simply Explained with Python: Normalized Mean Absolute Error (NMAE)
ACMer    Normalized Mean Absolute Error NMAE is a statistical measure used to assess the accuracy of a prediction model. It’s a variation of the Mean Absolute Error MAE , which is a common measure for regression models. Here’s how each term breaks down: Introduction to Mean Absolute Error MAE This is...
12  décembre     12h11
Stock Prices of Google and Microsoft Before and After Gemini
ACMer    A week ago, Google’s Gemini Demo was mind blowing but later it was reported that the demo video was edited, basically engineer prompted the AI offline and the use the text to voice engine to make the video look real time iterative. It looks to me it is cheating. Anyway, the Google stock price...
09  décembre     20h20
Teaching Kids Programming - Algorithms to Find the Unique Vertex of Zero Indegree in a Directed Acyclic Graph
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms There are n teams numbered from to n in a tournament; each team is also a node in a DAG. You are given the integer n and a indexed D integer array edges of length m representing the DAG, where edges indicates that there...
08  décembre     14h42
Differences Between Web2 and Web3 Domains
ACMer    Web or Web . Domains are those we mostly talk about nowadays. For example, when you type in https: helloacm.com in the browser, the helloacm.com is the Web . domain, which is controlled registered by a few centralized organizations. On the other hand, Web or Web . domains are based on...
06  décembre     23h28
Teaching Kids Programming - Algorithms to Find the Vertex of Zero Indegree in a Directed Acyclic Graph
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms . Find Champion I There are n teams numbered from to n in a tournament. Given a indexed D boolean matrix grid of size n n. For all i, j that i, j n and i j team i is stronger than team j if grid ,...
05  décembre     14h43
Boost System Performance By: Switching to Best Performance Power Mode at Power & Battery on Windows OS
ACMer    At System Power Battery, there is a Power Mode Setting which is default to Recommended . You can either choose Better Performance or Best Performance to Boost Your System immediately. In my case, switching to Best Performance immediately takes effects, and I notice that the CPU Fan...
04  décembre     01h00
Introduce to Solana Blockchain
ACMer    Solana is a high performance blockchain platform designed to provide fast, secure, and scalable decentralized applications and crypto currencies. It aims to address the scalability issues faced by other blockchain networks by utilizing a unique combination of technologies, including Proof of...
03  décembre     23h31
Algorithms to Compute the Sum of the Number of Digits for First N Natural Integers
ACMer    Given a integer n, find all the sum of the number of the digits up to n, for example, given n, we return, because, , , , are all digits, given n , we return , because, , , , , , , , are one digit and is digits. Write a python code. Find the Number of Digits for a Given Integer...
02  décembre     15h40
Teaching Kids Programming - Algorithms to Find the Lexicographically Smallest Palindrome
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms You are given a string s consisting of lowercase English letters, and you are allowed to perform operations on it. In one operation, you can replace a character in s with another lowercase English letter. Your task is to make s a...
28  novembre     23h40
Blockchain Hardfork vs Soft-fork
ACMer    In blockchain technology, both hard forks and soft forks are methods of updating or upgrading the protocol of a blockchain. However, they differ significantly in how they achieve these changes and the impact they have on the network. Hard Fork A hard fork is a significant change to the blockchain’s...
26  novembre     22h06
Teaching Kids Programming - Introduction to Two’s Complement (Storing Negative Integers)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms Two’s complement is a mathematical method used in computers to represent positive and negative integers. It’s the most common method for representing signed integers on computers. Two’s Complement Here’s how it works: Positive...
    14h25
Layer 1 and Layer2 in Blockchain Technology
ACMer    Layer and Layer are terms used to describe different levels or layers within blockchain technology, each with its unique role and characteristics in maintaining and scaling a blockchain network. For example, on Steem Blockchain, the Layer is the steemd, the consensus software that is run by...
20  novembre     23h47
Teaching Kids Programming - Last Moment Before All Ants Fall Out of a Plank
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms We have a wooden plank of the length n units. Some ants are walking on the plank, each ant moves with a speed of unit per second. Some of the ants move to the left, the other move to the right. When two ants moving in two...
16  novembre     16h09
Teaching Kids Programming - Algorithm to Generate a String With Characters That Have Odd Counts
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms Given an integer n, return a string with n characters such that each character in such string occurs an odd number of times. The returned string must contain only lowercase English letters. If there are multiples valid strings,...
15  novembre     20h06
Teaching Kids Programming - 0 1 Knapsack: Length of the Longest Subsequence That Sums to Target (Recursion Memoization Top Down Dynamic Programming)
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms You are given a indexed array of integers nums, and an integer target. Return the length of the longest subsequence of nums that sums up to target. If no such subsequence exists, return . A subsequence is an array that can be...
11  novembre     16h47
Teaching Kids Programming - Recursive Algorithms to Compute the K-th Symbol in Grammar
ACMer    Teaching Kids Programming: Videos on Data Structures and Algorithms We build a table of n rows indexed . We start by writing in the st row. Now in every subsequent row, we look at the previous row and replace each occurrence of with , and each occurrence of with . For example, for n ...
09  novembre     00h29
Introduction to Elastic Collision (Physics)
ACMer    An elastic collision is a type of collision in which two objects collide and bounce back without undergoing any permanent deformation or generating heat, thus conserving both kinetic energy and momentum. In other words, in an elastic collision, the total kinetic energy of the system composed of...