• ## Orange Boy Can You Solve It Out? Ep. 61

思考题 from Maths homework again... 数学小题两道 Problem A You are given a bipartite graph G, find a proper coloring of the complement of G that uses minimum colors. |G|\leq 100 Problem B Given integer N. Find any n\geq N such that n+\varphi(n) is ……
XGN 2024年5月22日
• ## Orange Boy Can You Solve It Out? Ep. 60

Solved! Difficulty: Div2C :O 竟然有60期了！！ 本期题目来源于Group Theory作业，，，难度不高 Congratulations on the 60th entry!! This problem is from my Group Theory homework (not very hard). Z(Sym(n))=ONE In the world of MATHS, a permutation i……
XGN 2024年4月29日
• ## Orange Boy Can't You Solve It Out? Ep. 59

思考题 aimed for inexperienced participants? Silenced! Ookami and her teammates are taking an English class. The team has n people(animals?) in total. Initially, each person can raise his/her hand and speak freely. However, once a student has raise……
XGN 2023年12月19日
• ## Orange Boy Can You Solve It Out? Ep. 58

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……
XGN 2023年12月6日
• ## Green Boy Can't You Solve It Out? Ep. 2

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……
XGN 2023年10月22日
• ## Orange Boy Can You Solve It Out? Ep. 57

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……
XGN 2023年10月7日
• ## Announcement on Solutions for Orange Boy Can You Solve It Out

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……
XGN 2023年10月6日
• ## Orange Boy Can You Solve It Out? Ep. 56

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,……
XGN 2023年10月6日
• ## Orange Boy Can You Solve It Out? Ep. 55

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……
XGN 2023年7月20日
• ## Orange Boy Can You Solve It Out? Ep. 54

Solved! Difficulty: Div2C 思考题 in dreamland Construct it XGN dreamt about the following problem when sleeping: You are given a positive integer n (2\leq n\leq 10^8). Output an arithmetic expression that yields the value n with the following……
XGN 2023年6月3日