Footprints of Happy Turtle

1. Problem   BOJ_1708 is the convex hull problems solved by Convex Hull algorithm. The levels of problem are Platinum 5.(Link of the problem of BOJ) Inputs The number of the points $N (3\leq N \leq 100,000)$ x-coordinate and y-coordinate of points $| x|, | y| \leq 40,000 $ Outputs The number of points of the convex hull covering all... Read More

1. Problem   BOJ_17386 and BOJ_17387 are the intersection of two lines problems solved by Counter Clockwise(CCW) algorithm. The levels of problem are Gold 3 and Gold 2, respectively.(Link of BOJ 17386)(Link of BOJ 17387) Inputs There are two line $L_1$ and $L_2$ in $\mathbb{Z}^2$. The endpoints of $L_1$ is $(x_1, y_1)$ and $(x_2, y_2)$. ... Read More

1. Problem   BOJ_1602 is the problem solved by Floyd-Warshall algorithm. The level of problem is Platinum 4.(Link of the problem of BOJ) Inputs The number of cities $N (2 \leq N \leq 500)$ The number of roads $M (0 \leq M \leq 10,000)$ The number of queries $Q (0 \leq Q \leq 40,000)$ $N$ rows: The time $t$ for the dog to bully cat in... Read More

1. Segment Tree   Segment Tree is a data structure to solve queries about range(e.g. RMQ, Prefix Sum). Segment Tree is often used when people solve problems of Online Judges or coding tests of recruitment process of companies. fig 1. Segment Tree for Prefix Sum Query Topologies $I$ is whole interval of given data. $T$ is the segment tr... Read More

LCA Problem Series LCA ①) Linear LCA query LCA ②) LCA query using Sparse Table LCA ③) LCA query using Segment Tree LCA ④) LCA reducted RMQ 1. Problem Input: a rooted tree $T$ of $n$ nodes two nodes $u$, $v$ in $T$ Output: the least ... Read More

LCA Problem Series LCA ①) Linear LCA query</span LCA ②) LCA query using Sparse Table LCA ③) LCA query using Segment Tree LCA ④) LCA reducted RMQ 1. Problem Input: a rooted tree $T$ of $n$ nodes two nodes $u$, $v$ in $T$ Output: t... Read More

1. Problem   BOJ_2516 is the problem solved by a naive solution. The level of problem is Platinum 4.(Link of the problem of BOJ) Inputs The number of monkeys $N (3 \leq N \leq 100,000)$ $N$ rows: The number of hostile monkeys of the $i$th monkey, the indices of hostile monkeys Conditions The maximal number of hostile monkeys of a mo... Read More

  PyTorch is a powerful deep learning module. There are two version of PyTorch, PyTorch CPU and PyTorch GPU. If you want to run own program more fast, you need to use PyTorch GPU. In this post, I introduce how to install the module in Anaconda env. 1. Check the versions of dependencies   To use PyTorch GPU, you must already install NVIDIA CUD... Read More

  In this post, I introduce how to set Gitblog development enviroment using Ruby and Jekyll bundler in Windows OS. After setting, we can check the pages in localhost:4000 befor publishing the pages. 1. Setting Install Ruby+Dvkit from RubyInstaller Downloads. Select the recommended version that is emphasized. Run the do... Read More

1. Error CondaSSLError: OpenSSL appears to be unavailable on this machine. OpenSSL is required to download and install packages. Exception: HTTPConnectionPool(host=’reop.anaconda.com’, port=443): Max retries exceeded with url: /pkgs/main/win-64/setuptools-65.6.3-py310haa95532_0.conda (Caused by SSLError(“Can’t connect to HTTPS URL because t... Read More

1. Markdown inline math   Generally, Github Markdown supprots inline math formulas, using $ keyword. And, using $$, you can post display formulas $x + 1 = 2$ \(x + 1 = 2\) 2. MD code problem and an alternative   However, when I write my blog, this code is not work. Differently from Github Markdown, a website launched by Github Page usi... Read More

1. Statistics in AI fig 1. Probability density function imitation   The goal of AI imitates a function in real world. If an AI model works well, it can predicts deterministic target. However, real world consists probability density. So, There is not always deterministic value. The true goal of AI is imitates probability density function in ... Read More

1. Word Embedding   Because language that consist of words, prepositionas and etc is not a computable object, it have to be converted to some computable representation. So, in data processing stage, input texts is converted to a vector, and it is called ‘Word Embedding’. There are a lot of word embedding methods. In this post, ‘One-Hot Encodi... Read More

1. Problem   BOJ_2300 is the problem of dynamic programming. The level of problem is Gold 3.(Link of the problem of BOJ) Inputs The number of buildings: N (1≤N≤10,000) The position of ith building for each row: x, y (|x|, |y| ≤ 1,000,000) Conditions The y-coordinate of all buildings are not 0. ... Read More

1. Error ImportError: cannot import name ‘toimage’ from ‘scipy.misc’   I was learning image processing in DL lecture. I had to convert float32 matrices into images. In the lecture, the code below is proposed.   matrices[i].shape is 32, 32, 3, and ‘matrices’ save float32 value. The last dimension whose shape is 3 means the channel of im... Read More

  This post is the outline of metrics used in NLP. So, there are only name, category, some relation with other metrics and short description. I will write post about each metric, and link them in this post. * Two Terms of Evaluation Instrinsic Evaluation: Evaluation by human. It is most perfect evaluation. Depending on who scores, there is... Read More

1. Problem   BOJ_2533 is the problem of dynamic programming using general tree. The level of problem is Gold 3.(Link of the problem of BOJ)   Input is the number of vertex(node) of tree N (2 <= N <= 1,000,000), edges(v, w), where v and w is vertex(node) of tree. There are two kinds of vertices, Early adopter(TEA), and Not Early adpopter(... Read More

1. Code Block   In markdown, we can make code block. Input Output 2. What codes we can use Language Code Title Bash bash C# cs C++ cpp CSS css Diff diff HTML, XML html ... Read More

1. Favicon   Favicon is main icon of your git blog. If you set yout favicon, then you can see what like the pic below. 2. How to set a favicon   First, I am using the jekyll theme, ‘Yat’. So, What I introduce in this section is only applied to the same theme. Prepare an image that you want to set for your favicon. Go to realfavicongen... Read More

  Anaconda is open source distribution that aims to simplify package management and deployment. It is often used to manage python project. You can create and use independent virtual environment. With conda, you can create, export, list, remove, and update environments that have different versions of Python and/or packages installed in them. S... Read More

1. Problem   BOJ_2751 is the problem of sorting numbers using array. Given integers, sort it in an increasing order. Input is the number of the integers named N (1 <= N <= 1,000,000) and the integers which never overalp. Output is the integers, which were inputted, in increasing order for each line. The time limit of the problem is 2 sec... Read More

1. Problem   BOJ_2750 is the problem of sorting numbers using array. Given integers, sort it in an increasing order. Input is the number of the integers,N (1 <= N <= 1,000), and the integers which never overlap. Output is the integers, which were inputed, in increasing order for each line. The time limit of the problem is 1 second, and t... Read More

  If you want to make a bookmark, make the hyperlink connected a part of current page with the code below.   Also, you can link some url with href  like the code below. Read More

안녕하세요.   간단한 모바일 게임을 출시하게 되어 글을 씁니다. 저는 말도 많고 탈도 많았던 ‘GameMakers’ 활동에서 ‘4Masters’라는 소규모 팀의 팀장이자 기획자로 활동해왔습니다. 비록 대략 9개월간 진행한 메인 프로젝트는 기획적 부분의 큰 오류로 인하여 중단하게 되었지만 그 기간 동안 같이 동고동락한 우리 팀원들의 열정 덕분에 결과물을 낼 수 있게 되었습니다. 초보인 우리들의 이야기, ‘디비진 디벨롭’   ‘디비진디벨롭’은 대화형 시뮬레이션 게임입니다. 초보 게임 개발팀에서 활동하는 아트 디자이너가 되어 초보 기획자인 팀장과의 대화를 잘 이끌어나가야 합니다. 만약 선택지를 잘 고르지 못할 ... Read More