Posts by Tag

Blind75 - Linked List Manipulation (포인터의 흐름과 간격의 미학)

March 4, 2026 2 minute read

Linked List (연결 리스트) 핵심 개념

Blind75 - Linked List Manipulation (The Art of Pointer Flow and Gap Keeping)

March 4, 2026 3 minute read

Core Concepts of Linked Lists

System Design - Scalable & Reliable Webhook System

February 27, 2026 5 minute read

Scalable & Reliable Webhook System Design

System Design - Scalable & Reliable Webhook System (EN)

February 27, 2026 5 minute read

Scalable & Reliable Webhook System Design

System Design - Scalable URL Shortener

February 26, 2026 4 minute read

Scalable URL Shortener System Design

System Design - Scalable URL Shortener

February 26, 2026 4 minute read

Scalable URL Shortener System Design

Blind75 - Valid Parentheses (스택과 문자열 소거법)

February 19, 2026 1 minute read

Valid Parentheses (유효한 괄호)

Blind75 - Valid Parentheses (Stack & String Elimination)

February 19, 2026 2 minute read

Valid Parentheses

Blind75 - Longest Repeating Character Replacement (슬라이딩 윈도우와 빈도수 체크)

February 19, 2026 2 minute read

Longest Repeating Character Replacement (대치 후 가장 긴 반복 문자열)

Blind75 - Longest Repeating Character Replacement (Sliding Window & Frequency Check)

February 19, 2026 2 minute read

Longest Repeating Character Replacement

Blind75 - Longest Substring Without Repeating Characters (문자열 슬라이싱과 슬라이딩 윈도우)

February 18, 2026 1 minute read

Longest Substring Without Repeating Characters (중복 없는 가장 긴 부분 문자열)

Blind75 - Longest Substring Without Repeating Characters (String Slicing & Sliding Window)

February 18, 2026 2 minute read

Longest Substring Without Repeating Characters

Blind75 - Best Time to Buy and Sell Stock (로직 교정과 슬라이딩 윈도우)

February 18, 2026 2 minute read

Best Time to Buy and Sell Stock (주식 최대 수익 찾기)

Blind75 - Best Time to Buy and Sell Stock (Logic Correction & Sliding Window)

February 18, 2026 2 minute read

Best Time to Buy and Sell Stock

Blind75 - Valid Palindrome (로직 교정과 투 포인터)

February 17, 2026 1 minute read

Valid Palindrome (팰린드롬 검증)

Blind75 - Valid Palindrome (Logic Correction & Two Pointer)

February 17, 2026 2 minute read

Valid Palindrome

Blind75 - Container with Most Water (투 포인터 접근법)

February 17, 2026 2 minute read

Container with Most Water (가장 많은 물을 담을 수 있는 용기)

Blind75 - Container with Most Water (Two Pointer Approach)

February 17, 2026 2 minute read

Container with Most Water

Blind75 - 3Sum (중복 처리의 늪과 투 포인터의 효율성)

February 17, 2026 2 minute read

3Sum (세 수의 합)

Blind75 - 3Sum (The Pitfall of Duplicates & Two Pointer Efficiency)

February 17, 2026 2 minute read

3Sum

Blind75 - Top K Frequent Elements (Heap & Bucket Sort)

February 16, 2026 2 minute read

Top K Frequent Elements

Blind75 - Longest Consecutive Sequence (정렬 기반 접근법)

February 16, 2026 1 minute read

Longest Consecutive Sequence (가장 긴 연속된 요소)

Blind75 - Longest Consecutive Sequence (Sorting-Based Approach)

February 16, 2026 2 minute read

Longest Consecutive Sequence

Blind75 - Group Anagrams (Hash Map & Visited)

February 16, 2026 1 minute read

Group Anagrams (아나그램 그룹화)

Blind75 - Group Anagrams (Hash Map & Visited)

February 16, 2026 2 minute read

Group Anagrams

Blind75 - Encode and Decode Strings (Chunked Encoding)

February 16, 2026 1 minute read

Encode and Decode Strings (문자열 인코딩과 디코딩)

Blind75 - Encode and Decode Strings (Chunked Encoding)

February 16, 2026 2 minute read

Encode and Decode Strings

머신러닝 회귀 예측

September 26, 2023 17 minute read

First Test Page Created

September 26, 2023 less than 1 minute read

Hi there! I am Dongchan Kim

99클럽 타임어택 보너스 문제풀이 [센서]

February 17, 2025 1 minute read

센서, 저번기수 타임어택 문제이다.

JAVA Coding Test Dynamic Programming

February 14, 2025 2 minute read

코딩테스트의 Dynamic Programming 과정을 한번 이해해보자

99클럽 타임어택 보너스 문제풀이 [소수 찾기]

February 8, 2025 3 minute read

저번 기수 문제 중 하나였다. 소수 찾기

99클럽 JAVA 코딩테스트 예시답안 13일차 [부등호]

February 5, 2025 2 minute read

부등호

99클럽 JAVA 코딩테스트 예시답안 12일차 [숫자 정사각형]

February 4, 2025 2 minute read

숫자 정사각형

99클럽 타임어택 보너스 문제풀이 [효율적인 해킹]

February 3, 2025 5 minute read

효율적인 해킹

99클럽 JAVA 코딩테스트 예시답안 11일차 [체스판 다시 칠하기]

February 2, 2025 2 minute read

체스판 다시 칠하기

99클럽 JAVA 코딩테스트 예시답안 10일차 [빙산]

January 24, 2025 3 minute read

빙산, 저번기수 타임어택 문제였다.

99클럽 JAVA 코딩테스트 예시답안 9일차 [이분 그래프]

January 23, 2025 2 minute read

이분 그래프

99클럽 JAVA 코딩테스트 예시답안 8일차 [단지번호붙이기]

January 22, 2025 3 minute read

단지번호붙이기

99클럽 JAVA 코딩테스트 예시답안 7일차 [숨바꼭질]

January 21, 2025 2 minute read

숨바꼭질

99클럽 JAVA 코딩테스트 예시답안 6일차 [할리갈리]

January 20, 2025 3 minute read

할리갈리

99클럽 타임어택 보너스 문제풀이 [입국심사]

January 20, 2025 2 minute read

입국심사

99클럽 JAVA 코딩테스트 예시답안 5일차 [세로읽기]

January 17, 2025 1 minute read

세로 읽기

99클럽 JAVA 코딩테스트 예시답안 4일차 [뜨거운 붕어빵]

January 16, 2025 1 minute read

뜨거운 붕어빵

99클럽 JAVA 코딩테스트 예시답안 3일차 [문자열 반복]

January 15, 2025 1 minute read

문자열 반복

99클럽 JAVA 코딩테스트 예시답안 2일차 [그대로 출력하기2]

January 14, 2025 1 minute read

그대로 출력하기 2

99클럽 JAVA 코딩테스트 예시답안 1일차 [문자열 내 P와 Y의 개수]

January 13, 2025 1 minute read

문자열 내 p와 y의 개수

Blind75 - Valid Parentheses (스택과 문자열 소거법)

February 19, 2026 1 minute read

Valid Parentheses (유효한 괄호)

Blind75 - Valid Parentheses (Stack & String Elimination)

February 19, 2026 2 minute read

Valid Parentheses

Blind75 - Longest Repeating Character Replacement (슬라이딩 윈도우와 빈도수 체크)

February 19, 2026 2 minute read

Longest Repeating Character Replacement (대치 후 가장 긴 반복 문자열)

Blind75 - Longest Repeating Character Replacement (Sliding Window & Frequency Check)

February 19, 2026 2 minute read

Longest Repeating Character Replacement

Blind75 - Longest Substring Without Repeating Characters (문자열 슬라이싱과 슬라이딩 윈도우)

February 18, 2026 1 minute read

Longest Substring Without Repeating Characters (중복 없는 가장 긴 부분 문자열)

Blind75 - Longest Substring Without Repeating Characters (String Slicing & Sliding Window)

February 18, 2026 2 minute read

Longest Substring Without Repeating Characters

Blind75 - Best Time to Buy and Sell Stock (로직 교정과 슬라이딩 윈도우)

February 18, 2026 2 minute read

Best Time to Buy and Sell Stock (주식 최대 수익 찾기)

Blind75 - Best Time to Buy and Sell Stock (Logic Correction & Sliding Window)

February 18, 2026 2 minute read

Best Time to Buy and Sell Stock

Blind75 - Valid Palindrome (로직 교정과 투 포인터)

February 17, 2026 1 minute read

Valid Palindrome (팰린드롬 검증)

Blind75 - Valid Palindrome (Logic Correction & Two Pointer)

February 17, 2026 2 minute read

Valid Palindrome

Blind75 - 3Sum (중복 처리의 늪과 투 포인터의 효율성)

February 17, 2026 2 minute read

3Sum (세 수의 합)

Blind75 - 3Sum (The Pitfall of Duplicates & Two Pointer Efficiency)

February 17, 2026 2 minute read

3Sum

Blind75 - Longest Consecutive Sequence (정렬 기반 접근법)

February 16, 2026 1 minute read

Longest Consecutive Sequence (가장 긴 연속된 요소)

Blind75 - Longest Consecutive Sequence (Sorting-Based Approach)

February 16, 2026 2 minute read

Longest Consecutive Sequence

Blind75 - Valid Parentheses (스택과 문자열 소거법)

February 19, 2026 1 minute read

Valid Parentheses (유효한 괄호)

Blind75 - Valid Parentheses (Stack & String Elimination)

February 19, 2026 2 minute read

Valid Parentheses

Blind75 - Longest Repeating Character Replacement (슬라이딩 윈도우와 빈도수 체크)

February 19, 2026 2 minute read

Longest Repeating Character Replacement (대치 후 가장 긴 반복 문자열)

Blind75 - Longest Repeating Character Replacement (Sliding Window & Frequency Check)

February 19, 2026 2 minute read

Longest Repeating Character Replacement

Blind75 - Longest Substring Without Repeating Characters (문자열 슬라이싱과 슬라이딩 윈도우)

February 18, 2026 1 minute read

Longest Substring Without Repeating Characters (중복 없는 가장 긴 부분 문자열)

Blind75 - Longest Substring Without Repeating Characters (String Slicing & Sliding Window)

February 18, 2026 2 minute read

Longest Substring Without Repeating Characters

Blind75 - Valid Palindrome (로직 교정과 투 포인터)

February 17, 2026 1 minute read

Valid Palindrome (팰린드롬 검증)

Blind75 - Valid Palindrome (Logic Correction & Two Pointer)

February 17, 2026 2 minute read

Valid Palindrome

Blind75 - Encode and Decode Strings (Chunked Encoding)

February 16, 2026 1 minute read

Encode and Decode Strings (문자열 인코딩과 디코딩)

Blind75 - Encode and Decode Strings (Chunked Encoding)

February 16, 2026 2 minute read

Encode and Decode Strings

iOS스터디 week7, 스위프트에서 날짜와 시간 다루기

August 23, 2024 2 minute read

UTC(Cordinated Universal Time)

iOS 스터디 week6. 스위프트 네트워크와 비동기 프로그래밍

August 14, 2024 6 minute read

네트워킹

iOS 스터디 week5. 프로토콜

August 7, 2024 4 minute read

프로토콜

iOS 스터디 week4. 구조체의 확장과 생성자 관련 세부사항

July 23, 2024 4 minute read

구조체의 확장과 생성자 관련 세부사항 확장에서도 생성자를 구현할 수 있지만, 모든 생성자를 구현할 수는 없다.

iOS스터디 week3, 계산속성과 저장속성

July 17, 2024 3 minute read

구조체(struct) and 클래스(class) 이 둘은 모두 객체지향 → 공통적으로 속성값(properties)은 같다. 저장속성, 지연(Lazy)저장속성, 계산속성(Computed), 타입속성, 속성 감시자(observer)

Swift 특이점①, 열거형(Enum)

July 14, 2024 7 minute read

열거형(Enumerations)

iOS스터디 week2, 컬렉션(collection)

July 11, 2024 8 minute read

스위프트 컬렉션

inout 입출력 파라미터, gaurd문, 옵셔널 바인딩

July 10, 2024 3 minute read

기존 파이썬이나 자바스크립트 문법을 알고 있기 때문에, 비슷한 방식의 문법구조와 관련된 건 스킵하기로 했다. 다만 Swift에서 꼭 알아야만 하는 문법과 이 언어의 특징과 같은 문법들은 꼼꼼하게 되짚어보자. (사실 이게 더 어려움;;)

Blind75 - Best Time to Buy and Sell Stock (로직 교정과 슬라이딩 윈도우)

February 18, 2026 2 minute read

Best Time to Buy and Sell Stock (주식 최대 수익 찾기)

Blind75 - Best Time to Buy and Sell Stock (Logic Correction & Sliding Window)

February 18, 2026 2 minute read

Best Time to Buy and Sell Stock

Blind75 - Valid Palindrome (로직 교정과 투 포인터)

February 17, 2026 1 minute read

Valid Palindrome (팰린드롬 검증)

Blind75 - Valid Palindrome (Logic Correction & Two Pointer)

February 17, 2026 2 minute read

Valid Palindrome

Blind75 - 3Sum (중복 처리의 늪과 투 포인터의 효율성)

February 17, 2026 2 minute read

3Sum (세 수의 합)

Blind75 - 3Sum (The Pitfall of Duplicates & Two Pointer Efficiency)

February 17, 2026 2 minute read

3Sum

Blind75 - Encode and Decode Strings (Chunked Encoding)

February 16, 2026 1 minute read

Encode and Decode Strings (문자열 인코딩과 디코딩)

Blind75 - Encode and Decode Strings (Chunked Encoding)

February 16, 2026 2 minute read

Encode and Decode Strings

Blind75 - Best Time to Buy and Sell Stock (로직 교정과 슬라이딩 윈도우)

February 18, 2026 2 minute read

Best Time to Buy and Sell Stock (주식 최대 수익 찾기)

Blind75 - Best Time to Buy and Sell Stock (Logic Correction & Sliding Window)

February 18, 2026 2 minute read

Best Time to Buy and Sell Stock

Blind75 - Container with Most Water (투 포인터 접근법)

February 17, 2026 2 minute read

Container with Most Water (가장 많은 물을 담을 수 있는 용기)

Blind75 - Container with Most Water (Two Pointer Approach)

February 17, 2026 2 minute read

Container with Most Water

Blind75 - 3Sum (중복 처리의 늪과 투 포인터의 효율성)

February 17, 2026 2 minute read

3Sum (세 수의 합)

Blind75 - 3Sum (The Pitfall of Duplicates & Two Pointer Efficiency)

February 17, 2026 2 minute read

3Sum

Blind75 - Longest Consecutive Sequence (정렬 기반 접근법)

February 16, 2026 1 minute read

Longest Consecutive Sequence (가장 긴 연속된 요소)

Blind75 - Longest Consecutive Sequence (Sorting-Based Approach)

February 16, 2026 2 minute read

Longest Consecutive Sequence

Blind75 - Longest Repeating Character Replacement (슬라이딩 윈도우와 빈도수 체크)

February 19, 2026 2 minute read

Longest Repeating Character Replacement (대치 후 가장 긴 반복 문자열)

Blind75 - Longest Repeating Character Replacement (Sliding Window & Frequency Check)

February 19, 2026 2 minute read

Longest Repeating Character Replacement

Blind75 - Longest Substring Without Repeating Characters (문자열 슬라이싱과 슬라이딩 윈도우)

February 18, 2026 1 minute read

Longest Substring Without Repeating Characters (중복 없는 가장 긴 부분 문자열)

Blind75 - Longest Substring Without Repeating Characters (String Slicing & Sliding Window)

February 18, 2026 2 minute read

Longest Substring Without Repeating Characters

Blind75 - Best Time to Buy and Sell Stock (로직 교정과 슬라이딩 윈도우)

February 18, 2026 2 minute read

Best Time to Buy and Sell Stock (주식 최대 수익 찾기)

Blind75 - Best Time to Buy and Sell Stock (Logic Correction & Sliding Window)

February 18, 2026 2 minute read

Best Time to Buy and Sell Stock

Blind75 - Longest Consecutive Sequence (정렬 기반 접근법)

February 16, 2026 1 minute read

Longest Consecutive Sequence (가장 긴 연속된 요소)

Blind75 - Longest Consecutive Sequence (Sorting-Based Approach)

February 16, 2026 2 minute read

Longest Consecutive Sequence

All about Sorting - HeapSort & QuickSort

May 12, 2025 5 minute read

HeapSort 메소드 정리

All about Sorting - SimpleSort & MergeSort

May 11, 2025 10 minute read

1. Sorting

Blind75 - Linked List Manipulation (포인터의 흐름과 간격의 미학)

March 4, 2026 2 minute read

Linked List (연결 리스트) 핵심 개념

Blind75 - Linked List Manipulation (The Art of Pointer Flow and Gap Keeping)

March 4, 2026 3 minute read

Core Concepts of Linked Lists

Blind75 - Container with Most Water (투 포인터 접근법)

February 17, 2026 2 minute read

Container with Most Water (가장 많은 물을 담을 수 있는 용기)

Blind75 - Container with Most Water (Two Pointer Approach)

February 17, 2026 2 minute read

Container with Most Water

System Design - Scalable & Reliable Webhook System

February 27, 2026 5 minute read

Scalable & Reliable Webhook System Design

System Design - Scalable & Reliable Webhook System (EN)

February 27, 2026 5 minute read

Scalable & Reliable Webhook System Design

System Design - Scalable URL Shortener

February 26, 2026 4 minute read

Scalable URL Shortener System Design

System Design - Scalable URL Shortener

February 26, 2026 4 minute read

Scalable URL Shortener System Design

System Design - Scalable & Reliable Webhook System

February 27, 2026 5 minute read

Scalable & Reliable Webhook System Design

System Design - Scalable & Reliable Webhook System (EN)

February 27, 2026 5 minute read

Scalable & Reliable Webhook System Design

System Design - Scalable URL Shortener

February 26, 2026 4 minute read

Scalable URL Shortener System Design

System Design - Scalable URL Shortener

February 26, 2026 4 minute read

Scalable URL Shortener System Design

System Design - Scalable & Reliable Webhook System

February 27, 2026 5 minute read

Scalable & Reliable Webhook System Design

System Design - Scalable & Reliable Webhook System (EN)

February 27, 2026 5 minute read

Scalable & Reliable Webhook System Design

System Design - Scalable URL Shortener

February 26, 2026 4 minute read

Scalable URL Shortener System Design

System Design - Scalable URL Shortener

February 26, 2026 4 minute read

Scalable URL Shortener System Design

System Design - Scalable & Reliable Webhook System

February 27, 2026 5 minute read

Scalable & Reliable Webhook System Design

System Design - Scalable & Reliable Webhook System (EN)

February 27, 2026 5 minute read

Scalable & Reliable Webhook System Design

System Design - Scalable URL Shortener

February 26, 2026 4 minute read

Scalable URL Shortener System Design

System Design - Scalable URL Shortener

February 26, 2026 4 minute read

Scalable URL Shortener System Design

System Design - Scalable & Reliable Webhook System

February 27, 2026 5 minute read

Scalable & Reliable Webhook System Design

System Design - Scalable & Reliable Webhook System (EN)

February 27, 2026 5 minute read

Scalable & Reliable Webhook System Design

System Design - Scalable URL Shortener

February 26, 2026 4 minute read

Scalable URL Shortener System Design

System Design - Scalable URL Shortener

February 26, 2026 4 minute read

Scalable URL Shortener System Design

너 통나무 들 자격 있어? XReal Summer Hackathon 회고록

July 6, 2025 4 minute read

본 글은 생성형 AI 도움없이 작성된 글로 다소 거칠 수 있습니다.

첫 아이디어톤 운영, 그리고 많은 시행착오들

September 13, 2024 1 minute read

돌돌, 또또, 또 너냐? 응 나다. 다시 동아리 임원진을 한다고? 또 너냐? -클템 해설-

2024 Google 새싹 해커톤 서울시 대회 수상 회고록

August 3, 2024 7 minute read

프롤로그 인간을 대체할 만한 AI의 발전, 개발직을 정말 내가 원하긴 하는지, 그래서 T자형 인간이 도대체 뭐일까에 대한 회의감 등등 지난 1년동안 참 많은 것들을 고민하며 지내온 것 같다. 이런 시간을 보내면서, VS code를 단 한번도 열어보지 않았고, 그 수북하고 초록색으로...

AI Utilization in XR Technology

May 13, 2025 1 minute read

Recently, there have been many tips on how to use ChatGPT effectively on the Internet. This skill is called Prompt Engineering. Some people are very good at ...

Unity XR Interaction Toolkit Core파트

January 2, 2025 1 minute read

Unity 개념학습 두 번째 포스팅

Unity XR Interaction Toolkit TroubleShooting

December 29, 2024 3 minute read

Unity 개념학습 첫 번째 포스팅

Power to the People, Through My Lens: An Interpretive Take on LLMs

April 12, 2025 2 minute read

Review of Andrej Karpathy’s X, who is Previously Director of AI @Tesla, founding team @OpenAI

Understanding MCP as a Software Engineer

April 4, 2025 3 minute read

What a fast moving industry! MCP totally changes whole the industy!🤯”

How GenAI is Transforming S/W Development

March 17, 2025 3 minute read

Don’t Think AI Is Taking Engineer Jobs! It’s Empowering Me!😅”

Blind75 - Top K Frequent Elements (Heap & Bucket Sort)

February 16, 2026 2 minute read

Top K Frequent Elements

Blind75 - Group Anagrams (Hash Map & Visited)

February 16, 2026 1 minute read

Group Anagrams (아나그램 그룹화)

Blind75 - Group Anagrams (Hash Map & Visited)

February 16, 2026 2 minute read

Group Anagrams

Three.js로 3D 플랫폼 개발 [Camera/Scene/Renderer]

January 16, 2025 2 minute read

Three.js를 이용한 3D 플랫폼 개발 개념공부

Three.js로 3D 플랫폼 개발 [Dom/SVG/Canvas]

January 8, 2025 2 minute read

Three.js를 이용한 3D 플랫폼 개발 개념공부

Three.js로 3D 플랫폼 개발 [Camera/Scene/Renderer]

January 16, 2025 2 minute read

Three.js를 이용한 3D 플랫폼 개발 개념공부

Three.js로 3D 플랫폼 개발 [Dom/SVG/Canvas]

January 8, 2025 2 minute read

Three.js를 이용한 3D 플랫폼 개발 개념공부

Three.js로 3D 플랫폼 개발 [Camera/Scene/Renderer]

January 16, 2025 2 minute read

Three.js를 이용한 3D 플랫폼 개발 개념공부

Three.js로 3D 플랫폼 개발 [Dom/SVG/Canvas]

January 8, 2025 2 minute read

Three.js를 이용한 3D 플랫폼 개발 개념공부

Unity XR Interaction Toolkit 이외에 기타 등등 ②

January 9, 2025 less than 1 minute read

Unity 개념학습 마지막 포스팅

Unity XR Interaction Toolkit 이외에 기타 등등

January 9, 2025 1 minute read

Unity 개념학습 마지막 포스팅

Unity XR Interaction Toolkit 이외에 기타 등등 ②

January 9, 2025 less than 1 minute read

Unity 개념학습 마지막 포스팅

Unity XR Interaction Toolkit 이외에 기타 등등

January 9, 2025 1 minute read

Unity 개념학습 마지막 포스팅

Maps and Sets

May 14, 2025 4 minute read

해싱 (Hashing)

JAVA Coding Test Hash

January 15, 2025 5 minute read

Hash

Binary Search Trees

April 28, 2025 11 minute read

BinarySearchTree는 삽입, 삭제, 검색에서 평균적으로 O(log n)의 시간 복잡도를 가진다. 그러나 최악의 경우에는 O(n) 시간 복잡도를 가질 수 있다. 이는 Array, ArrayList, LinkedList의 평균 O(n) 성능보다 훨씬 좋다.

Binary Trees

April 27, 2025 7 minute read

Understand binary-tree concepts and important properties, such as the Binary Tree Theorem and the External Path Length Theorem. Be able to perfor...

Blind75 - Encode and Decode Strings (Chunked Encoding)

February 16, 2026 1 minute read

Encode and Decode Strings (문자열 인코딩과 디코딩)

Blind75 - Encode and Decode Strings (Chunked Encoding)

February 16, 2026 2 minute read

Encode and Decode Strings

Blind75 - Container with Most Water (투 포인터 접근법)

February 17, 2026 2 minute read

Container with Most Water (가장 많은 물을 담을 수 있는 용기)

Blind75 - Container with Most Water (Two Pointer Approach)

February 17, 2026 2 minute read

Container with Most Water

Blind75 - Valid Parentheses (스택과 문자열 소거법)

February 19, 2026 1 minute read

Valid Parentheses (유효한 괄호)

Blind75 - Valid Parentheses (Stack & String Elimination)

February 19, 2026 2 minute read

Valid Parentheses

System Design - Scalable & Reliable Webhook System

February 27, 2026 5 minute read

Scalable & Reliable Webhook System Design

System Design - Scalable & Reliable Webhook System (EN)

February 27, 2026 5 minute read

Scalable & Reliable Webhook System Design

Blind75 - Linked List Manipulation (포인터의 흐름과 간격의 미학)

March 4, 2026 2 minute read

Linked List (연결 리스트) 핵심 개념

Blind75 - Linked List Manipulation (The Art of Pointer Flow and Gap Keeping)

March 4, 2026 3 minute read

Core Concepts of Linked Lists

Blind75 - Linked List Manipulation (포인터의 흐름과 간격의 미학)

March 4, 2026 2 minute read

Linked List (연결 리스트) 핵심 개념

Blind75 - Linked List Manipulation (The Art of Pointer Flow and Gap Keeping)

March 4, 2026 3 minute read

Core Concepts of Linked Lists

First Test Page Created

September 26, 2023 less than 1 minute read

Hi there! I am Dongchan Kim

First Test Page Created

September 26, 2023 less than 1 minute read

Hi there! I am Dongchan Kim

iOS스터디 week2, 컬렉션(collection)

July 11, 2024 8 minute read

스위프트 컬렉션

Swift 특이점①, 열거형(Enum)

July 14, 2024 7 minute read

열거형(Enumerations)

iOS 스터디 week4. 구조체의 확장과 생성자 관련 세부사항

July 23, 2024 4 minute read

구조체의 확장과 생성자 관련 세부사항 확장에서도 생성자를 구현할 수 있지만, 모든 생성자를 구현할 수는 없다.

Github 대용량 파일 업로드 삽질….

August 5, 2024 2 minute read

GIF는 어지간하면 올리지 말자… 회고록을 올리면서 영상 데이터는 올릴 수가 없어서 MOV 파일을 Gif로 변환하여 깃허브에 push를 했다.

iOS 스터디 week5. 프로토콜

August 7, 2024 4 minute read

프로토콜

iOS 스터디 week6. 스위프트 네트워크와 비동기 프로그래밍

August 14, 2024 6 minute read

네트워킹

OpenGL ES 3차원 컴퓨터그래픽스 수학

September 22, 2024 1 minute read

ⓒ 2019. JungHyun Han Korea University Seoul, All rights reserved.

OpenGL ES 3차원 컴퓨터그래픽스 모델링

September 23, 2024 2 minute read

ⓒ 2019. JungHyun Han Korea University Seoul, All rights reserved.

OpenGL ES 3차원 컴퓨터그래픽스 스케일링

September 24, 2024 3 minute read

ⓒ 2019. JungHyun Han Korea University Seoul, All rights reserved.

OpenGL ES 3차원 컴퓨터그래픽스 정점 처리

September 25, 2024 3 minute read

ⓒ 2019. JungHyun Han Korea University Seoul, All rights reserved.

OpenGL ES 3차원 컴퓨터그래픽스 GL & Shader

September 27, 2024 3 minute read

ⓒ 2019. JungHyun Han Korea University Seoul, All rights reserved.

OpenGL ES 3차원 컴퓨터그래픽스 Rasterizer

September 29, 2024 3 minute read

ⓒ 2019. JungHyun Han Korea University Seoul, All rights reserved.

OpenGL ES 3차원 컴퓨터그래픽스 이미지 텍스쳐링

October 4, 2024 4 minute read

ⓒ 2019. JungHyun Han Korea University Seoul, All rights reserved.

OpenGL ES 3차원 컴퓨터그래픽스 Lighting

October 5, 2024 3 minute read

ⓒ 2019. JungHyun Han Korea University Seoul, All rights reserved.

OpenGL ES 3차원 컴퓨터그래픽스 Output Merger

October 7, 2024 1 minute read

ⓒ 2019. JungHyun Han Korea University Seoul, All rights reserved.

OpenGL ES 3차원 컴퓨터그래픽스 Euler Transforms & Quaternion

October 12, 2024 2 minute read

ⓒ 2019. JungHyun Han Korea University Seoul, All rights reserved.

OpenGL ES 3차원 컴퓨터그래픽스 Euler Transforms & Quaternion

October 12, 2024 2 minute read

ⓒ 2019. JungHyun Han Korea University Seoul, All rights reserved.

OpenGL ES 3차원 컴퓨터그래픽스 Screen-space Object Manipulation

October 13, 2024 less than 1 minute read

ⓒ 2019. JungHyun Han Korea University Seoul, All rights reserved.

JAVA Coding Test Introduction

October 31, 2024 2 minute read

백준

JAVA Coding Test Stack

November 9, 2024 4 minute read

Stack(LIFO) 데이터의 입력과 출력 순서는 후입선출(FILO)방식이다. 데이터를 제한적으로 접근할 수 있는 구조이고, 한쪽 끝에서만 자료를 넣거나 뺄 수 있는 구조 (DFS) 스택은 거의 모든 애플리케이션을 만들 때 사용되는 자료구조로서, 스택과 연관된 알고리즘을 제대...

Unity XR Interaction Toolkit Interactor파트

January 5, 2025 4 minute read

Unity 개념학습 세 번째 포스팅

Unity XR Interaction Toolkit Interactable파트

January 7, 2025 3 minute read

Unity 개념학습 네 번째 포스팅

Unity XR Interaction Toolkit Locomotion 파트

January 8, 2025 2 minute read

Unity 개념학습 다섯 번째 포스팅

Unity XR Interaction Toolkit UI파트

January 8, 2025 1 minute read

Unity 개념학습 여섯 번째 포스팅

Three.js로 3D 플랫폼 개발 Transformation

January 22, 2025 1 minute read

Three.js를 이용한 3D 플랫폼 개발 개념공부

Three.js로 3D 플랫폼 개발 Transformation

January 22, 2025 1 minute read

Three.js를 이용한 3D 플랫폼 개발 개념공부

Three.js로 3D 플랫폼 개발 Geometry

January 24, 2025 2 minute read

Three.js를 이용한 3D 플랫폼 개발 개념공부

Unity Troubleshooting - infinite

January 25, 2025 1 minute read

하루종일 삽질한 플랫폼 크랙문제

Three.js로 3D 플랫폼 개발 Material

January 27, 2025 3 minute read

Three.js를 이용한 3D 플랫폼 개발 개념공부

Three.js로 3D 플랫폼 개발 Light

January 28, 2025 1 minute read

Three.js를 이용한 3D 플랫폼 개발 개념공부

JAVA Coding Test Greedy

January 30, 2025 4 minute read

코딩테스트의 Greedy 과정을 한번 이해해보자

Three.js로 3D 플랫폼 개발 Interaction & Event

February 4, 2025 2 minute read

Three.js를 이용한 3D 플랫폼 개발 개념공부

Three.js로 3D 플랫폼 개발 Interaction & Event

February 4, 2025 2 minute read

Three.js를 이용한 3D 플랫폼 개발 개념공부

JAVA Coding Test Brute-Force

February 5, 2025 4 minute read

코딩테스트의 brute force 과정을 한번 이해해보자

Unity 2D 프로젝트 트러블슈팅 [Prefabs]

February 8, 2025 2 minute read

Unity에서 Prefab을 처음 만들어보면서 공부한 내용을 기록해둔다.

Unity 2D 프로젝트 트러블슈팅 [Collider]

February 12, 2025 1 minute read

Unity에서 Collider를 처음 만들어보면서 공부한 내용을 기록해둔다.

Unity 2D 프로젝트 트러블슈팅 [Game Manager와 Singleton패턴]

February 15, 2025 1 minute read

Unity에서 Game Manager를 처음 만들어보면서 공부한 내용을 기록해둔다.

How GenAI is Transforming S/W Development

March 17, 2025 3 minute read

Don’t Think AI Is Taking Engineer Jobs! It’s Empowering Me!😅”

Understanding MCP as a Software Engineer

April 4, 2025 3 minute read

What a fast moving industry! MCP totally changes whole the industy!🤯”

Power to the People, Through My Lens: An Interpretive Take on LLMs

April 12, 2025 2 minute read

Review of Andrej Karpathy’s X, who is Previously Director of AI @Tesla, founding team @OpenAI

Binary Trees

April 27, 2025 7 minute read

Understand binary-tree concepts and important properties, such as the Binary Tree Theorem and the External Path Length Theorem. Be able to perfor...

Binary Search Trees

April 28, 2025 11 minute read

BinarySearchTree는 삽입, 삭제, 검색에서 평균적으로 O(log n)의 시간 복잡도를 가진다. 그러나 최악의 경우에는 O(n) 시간 복잡도를 가질 수 있다. 이는 Array, ArrayList, LinkedList의 평균 O(n) 성능보다 훨씬 좋다.

Priority Queue & Heap

April 29, 2025 6 minute read

Priority Queue

Priority Queue & Heap

April 29, 2025 6 minute read

Priority Queue

Risk Management Lessons from the SKT USIM Hacking Incident

May 2, 2025 3 minute read

In April 2025, SK Telecom faced a major security breach involving unauthorized access to USIM data. This article analyzes the timeline, response gaps, and ke...

Risk Management Lessons from the SKT USIM Hacking Incident

May 2, 2025 3 minute read

In April 2025, SK Telecom faced a major security breach involving unauthorized access to USIM data. This article analyzes the timeline, response gaps, and ke...

All about Sorting - SimpleSort & MergeSort

May 11, 2025 10 minute read

1. Sorting

All about Sorting - SimpleSort & MergeSort

May 11, 2025 10 minute read

1. Sorting

All about Sorting - SimpleSort & MergeSort

May 11, 2025 10 minute read

1. Sorting

All about Sorting - SimpleSort & MergeSort

May 11, 2025 10 minute read

1. Sorting

All about Sorting - HeapSort & QuickSort

May 12, 2025 5 minute read

HeapSort 메소드 정리

All about Sorting - HeapSort & QuickSort

May 12, 2025 5 minute read

HeapSort 메소드 정리

AI Utilization in XR Technology

May 13, 2025 1 minute read

Recently, there have been many tips on how to use ChatGPT effectively on the Internet. This skill is called Prompt Engineering. Some people are very good at ...

Maps and Sets

May 14, 2025 4 minute read

해싱 (Hashing)

Maps and Sets

May 14, 2025 4 minute read

해싱 (Hashing)

Maps and Sets

May 14, 2025 4 minute read

해싱 (Hashing)

Dynamic Programming

June 6, 2025 4 minute read

Dynamic Programming

Graph

June 7, 2025 3 minute read

Graph 우리가 흔히 생각하는 ‘그래프(chart)’가 아니라, 요소 간의 관계를 표현하는 자료구조임. 여러 요소가 어떻게 연결되어 있는지를 표현함. 예시: SNS에서 사용자는 서로 팔로우하거나 팔로우당함 → 단순 배열이나 트리로는 표현이 어려움.

Blind75 - Top K Frequent Elements (Heap & Bucket Sort)

February 16, 2026 2 minute read

Top K Frequent Elements

Blind75 - Top K Frequent Elements (Heap & Bucket Sort)

February 16, 2026 2 minute read

Top K Frequent Elements