B1. Character Swap (Easy Version) This problem is different from the hard version. In this version Ujan makes exactly one exchange. You can hack this problem only if you solve both problems. After struggling and failing many times, Ujan decided to tr…

This problem is different from the hard version. In this version Ujan makes exactly one exchange. You can hack this problem only if you solve both problems. After struggling and failing many times, Ujan decided to try to clean up his house again. He…

B2. Character Swap (Hard Version) This problem is different from the easy version. In this version Ujan makes at most 2…

This problem is different from the easy version. In this version Ujan makes at most 2n2n swaps. In addition, k≤1000,n≤50k≤1000,n≤50 and it is necessary to print swaps themselves. You can hack this problem if you solve it. But you can hack the previou…

D2. RGB Substring (hard version) inputstandard input outputstandard output The only difference between easy and hard versions is the size of the input. You are given a string…

Brain's Photos 题目链接: http://codeforces.com/contest/707/problem/A Description Small, but very brave, mouse Brain was not accepted to summer school of young villains. He was upset and decided to postpone his plans of taking over the world, but to becom…

C. Efim and Strange Grade 题目连接: http://codeforces.com/contest/719/problem/C Description Efim just received his grade for the last test. He studies in a special school and his grade can be equal to any positive decimal fraction. First he got disappoin…

A. Whose sentence is it? Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/312/problem/A Description One day, liouzhou_101 got a chat record of Freda and Rainbow. Out of curiosity, he wanted to know which sentences were said…

A. Vitya in the Countryside 题目连接: http://codeforces.com/contest/719/problem/A Description Every summer Vitya comes to visit his grandmother in the countryside. This summer, he got a huge wart. Every grandma knows that one should treat warts when the…

A. Meeting of Old Friends 题目连接: http://codeforces.com/contest/714/problem/A Description Today an outstanding event is going to happen in the forest - hedgehog Filya will come to his old fried Sonya! Sonya is an owl and she sleeps during the day and s…

B. Vanya and Food Processor 题目连接: http://www.codeforces.com/contest/677/problem/B Description Vanya smashes potato in a vertical food processor. At each moment of time the height of the potato in the processor doesn't exceed h and the processor smash…

任意门:http://codeforces.com/contest/1118/problem/F1 F1. Tree Cutting (Easy Version) time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given an undirected tree of nn vertices. Some vert…

B. Ohana Cleans Up Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/554/problem/B Description Ohana Matsumae is trying to clean a room, which is divided up into an n by n grid of squares. Each square is initially either clea…

B. Gerald is into Art Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/560/problem/B Description Gerald bought two very rare paintings at the Sotheby's auction and he now wants to hang them on the wall. For that he bought a…

C. Bear and Prime 100 题目连接: http://www.codeforces.com/contest/680/problem/C Description This is an interactive problem. In the output section below you will see the information about flushing the output. Bear Limak thinks of some hidden number - an i…

Bus to Udayland 题目链接: http://codeforces.com/contest/711/problem/A Description ZS the Coder and Chris the Baboon are travelling to Udayland! To get there, they have to get on the special IOI bus. The IOI bus has n rows of seats. There are 4 seats in e…

B. Case of Fake Numbers Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/556/problem/B Description Andrewid the Android is a galaxy-famous detective. He is now investigating a case of frauds who make fake copies of the famou…

A. Kyoya and Photobooks Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/554/problem/A Description Kyoya Ootori is selling photobooks of the Ouran High School Host Club. He has 26 photos, labeled "a" to "z", a…

A. Wilbur and Swimming Pool Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/596/problem/A Description After making bad dives into swimming pools, Wilbur wants to build a swimming pool in the shape of a rectangle in his back…

A. The Child and Toy Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/438/problem/A Description On Children's Day, the child got a toy from Delayyy as a present. However, the child is so naughty that he can't wait to destroy…

C. Duff and Weight Lifting Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/588/problem/C Description Recently, Duff has been practicing weight lifting. As a hard practice, Malek gave her a task. He gave her a sequence of wei…

A. Currency System in Geraldion Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/560/problem/A Description A magic island Geraldion, where Gerald lives, has its own currency system. It uses banknotes of several values. But t…

A. Kefa and First Steps Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/580/problem/A Description Kefa decided to make some money doing business on the Internet for exactly n days. He knows that on the i-th day (1 ≤ i ≤ n) h…

A. Fake NP time limit per test:1 second memory limit per test:256 megabytes input:standard input output:standard output Tavak and Seyyed are good friends. Seyyed is very funny and he told Tavak to solve the following problem instead of longest-path.…

https://codeforces.com/contest/1118/problem/F1 #include<bits/stdc++.h> using namespace std; int n; vector<int> color; vector<vector<int> > tree; ,blue=; ; pair<){ ); ); ;i<tree[v].size();i++){ int u=tree[v][i]; if(u!=p){//避免回…

B. Chris and Magic Square 题目连接: http://www.codeforces.com/contest/711/problem/B Description ZS the Coder and Chris the Baboon arrived at the entrance of Udayland. There is a n × n magic grid on the entrance which is filled with integers. Chris notice…

C. Alyona and the Tree 题目连接: http://www.codeforces.com/contest/682/problem/C Description Alyona decided to go on a diet and went to the forest to get some apples. There she unexpectedly found a magic rooted tree with root in the vertex 1, every verte…

D. Gifts by the List 题目连接: http://www.codeforces.com/contest/681/problem/D Description Sasha lives in a big happy family. At the Man's Day all the men of the family gather to celebrate it following their own traditions. There are n men in Sasha's fam…

B. Bear and Finding Criminals 题目连接: http://www.codeforces.com/contest/680/problem/B Description There are n cities in Bearland, numbered 1 through n. Cities are arranged in one long row. The distance between cities i and j is equal to |i - j|. Limak…

A. Bear and Five Cards 题目连接: http://www.codeforces.com/contest/680/problem/A Description A little bear Limak plays a game. He has five cards. There is one number written on each card. Each number is a positive integer. Limak can discard (throw out) s…