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……

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……

Solved! Difficulty: Div2D-Div2E Note: this problem is drafted on 2019/7/30 by XGN and not released. It's now released on 2022/1/2 by Zzzyt under his permission. Statement Yuqi has an rooted indexed tree T of N nodes indexed from 1 to N. The n……

Solved! Difficulty: Div2D Long time no see 思考题 Tree Traversing Hikari has a tree of N nodes. The node #1 is the root. Initially she is at node 1. She can do one of the following three operations: - Move to any adjacant node with cost 1 - M……

Solved! Difficulty: Div2E-Div2F If you prefer easier problem, please visit here 思考题 for dw Childish War (Hard) Miss. Broken Tail(Wei Duan) is the Math teacher of NFLS Class 8 Junior 3.She is a kind teacher. Miss. East(Fang Dong) is the Mat……

Solved! Difficulty: Div2D-Div2E If you prefer harder problem, please visit here 思考题 for dw Childish War (Easy) Miss. Broken Tail(Wei Duan) is the Math teacher of NFLS Class 8 Junior 3.She is a kind teacher. Miss. East(Fang Dong) is the Mat……

Solved! Difficulty: Div2B-Div2C 思考题 that seems easy A perfect word Given N strings. Find out a longest string so that each substring of it is one of the N strings. Example Input str={a,t,at,orange} Output at Constriants Subtask 1(30%):N<……

Solved! Difficulty: ?? 思考题 for everyone Man on Graph You are given M chains each of N+1 nodes. We call the i-th node on the j-th chain (j,i-1). We define a bridge edge connecting (a,b) and (c,d) as follows: - a≠c - b=d - b and d don't equa……

Solved! Difficulty: Div2E 思考题for everyone Dynamic DP You are given: integer arrays A and dp of length N. integer arrays l and r of length N. For each 2\leq i\leq N,1\leq l_i\leq r_i\leq i-1 Known: dp_1=A_1 dp_i=min(dp[l_i,r_i])+A_i for 2\l……