Solved! Difficulty: Div2 C 思考题 in mid autumn LianLi Branches Wulpit has drawn n nodes(indexed from 1 to n) and n-m edges on paper for homework assignments. They form m rooted trees (aka a forest). However, when she went to the toilet, Fely……

Solved! Difficulty: Div2B 1 problem for div3 participants. Beautiful Dice Painting When Epis is bored, she will draw dices. The canvas contains n*n dots. Initially they are all white. You need to paint exactly v dots black so that the final c……

trivial 思考题 I am Banach This is a classic problem by Banach nearly without any change. There are N boys and M girls. Each boy loves a single girl and each girl loves a single boy. Your task is to divide the boys into two groups A_0 and A_1 and t……

Starting from today, we will try to write tutorials and rate difficulties for already solved Orange Boy Can You Solve It Out?(OBCYSIO) problems and separate them from unsolved/unsolvable ones. There's a new category called Solved OBCYSIO and you ca……

思考题 during OI recovery Rubbish Problem Maybe you have heard of the evil problem Hilbert's Hedge Maze and here's another very fun problem! You have n items arranged in rows. Each row contains r items and the items are arranged from left to right,……

概述 本文为XGN（后文称笔者）与其母（后文称母）于令和五年八月六日到十四日的日本国游记，在HHS博客上发表，XGN博客上转录。 「日行紀要」（にこうきよう）？ 在笔者之前，已经有一篇翔实而又生动的游记——日本国游记 笔者不及Z氏的文笔和才华，本文也只是简单概述所……

  我喜欢七月的阳光，虽然炽烈炫目，却让万物都在盛夏绽放出最旺盛的生命；我喜欢七月的温度，即使热浪滚滚，也能在穿过时光与美好的时候感受着酣畅淋漓的畅快。可是也许，我喜欢七月的这一切，更是因为在这个季节，我们可以暂且抛去身后的忙碌，来一场说走就走的旅行……

思考题 with hard-to-write checker and interactor Peripheral Lightup! Note: this is not a traditional problem. Follow the instruction in the statement to help construct your solution Lead-in: The Palace is celebrating a festival with LED lights! Ins……

  趁着高考出分之后，填报志愿之前的间隙，我和小龙一起去了溧阳。时间有限，只够游玩了天目湖和南山竹海这两个最著名的景点，但是整体体验上还是相当不错的。 高铁去溧阳，车程只有半小时   溧阳地处江苏，浙江，安徽三省交界之地，距离南京只有三十分钟的高铁车程……

Have you ever imagined a crossover between Touhou and Spice&Wolf? Now there is! Introduction S&W:MoF is a fangame of Touhou and Spice and Wolf: My year with Holo. In the game, the player roleplays the merchant Lawrence and embarks on a jour……