| Problem Name | Online Judge | Year | Contest | Difficulty Level | |
|---|---|---|---|---|---|
| 1 | Longest path in a tree | SPOJ | 1 | ||
| 2 | Chocolate | SPOJ | 1 | ||
| 3 | Kefa and Park | Codeforces | Codeforces Round #321 (Div. 2) | 1 | |
| 4 | k-Tree | Codeforces | Codeforces Round #247 (Div. 2) | 1 | |
| 5 | Xenia and Bit Operations | Codeforces | Codeforces Round #197 (Div. 2) | 1 | |
| 6 | Party | Codeforces | Codeforces Beta Round #87 (Div. 1 Only) & Codeforces Beta Round #87 (Div. 2 Only) | 1 | |
| 7 | Nice Binary Trees | SPOJ | 1 | ||
| 8 | Pashmak and Garden | Codeforces | Codeforces Round #261 (Div. 2) | 1 | |
| 9 | Binary Search Tree | UVA | 2 | ||
| 10 | Bear and Forgotten Tree 3 | Codeforces | VK Cup 2016 - Round 1 | 2 | |
| 11 | Reposts | Codeforces | VK Cup 2015 - Qualification Round 1 | 2 | |
| 12 | Xor-tree | Codeforces | Codeforces Round #245 (Div. 1) & Codeforces Round #245 (Div. 2) | 2 | |
| 13 | Tree _order | SPOJ | 2 | ||
| 14 | Timofey and a tree | Codeforces | Codeforces Round #395 (Div. 1) & Codeforces Round #395 (Div. 2) | 2 | |
| 15 | Journey | Codeforces | Codeforces Round #428 (Div. 2) | 2 | |
| 16 | Fibonacci System | Live Archive | 2008 | Europe - Northeastern | 2 |
| 17 | Choosing Capital for Treeland | Codeforces | Codeforces Round #135 (Div. 2) | 3 | |
| 18 | Distance in Tree | Codeforces | VK Cup 2012 Round 1 | 3 | |
| 19 | Ants Colony | UVA | 3 | ||
| 20 | Misha and Forest | Codeforces | Codeforces Round #285 (Div. 2) & Codeforces Round #285 (Div. 1) | 3 | |
| 21 | Interesting Array | Codeforces | Codeforces Round #275 (Div. 1) & Codeforces Round #275 (Div. 2) | 3 | |
| 22 | Valera and Elections | Codeforces | Codeforces Round #216 (Div. 2) | 3 | |
| 23 | Alyona and the Tree | Codeforces | Codeforces Round #358 (Div. 2) | 3 | |
| 24 | Anton and Making Potions | Codeforces | Codeforces Round #379 (Div. 2) | 3 | |
| 25 | Okabe and Boxes | Codeforces | Codeforces Round #420 (Div. 2) | 3 | |
| 26 | Vasiliy's Multiset | Codeforces | Codeforces Round #367 (Div. 2) | 3 | |
| 27 | AVL Tree | SPOJ | 3 | ||
| 28 | Fools and Roads | Codeforces | Codeforces Round #121 (Div. 1) & Codeforces Round #121 (Div. 2) | 4 | |
| 29 | Eternal Victory | Codeforces | Codeforces Beta Round #57 (Div. 2) | 4 | |
| 30 | Roads not only in Berland | Codeforces | Codeforces Beta Round #25 (Div. 2 Only) | 4 | |
| 31 | Civilization | Codeforces | Codeforces Round #260 (Div. 1) & Codeforces Round #260 (Div. 2) | 4 | |
| 32 | Count Minimum Spanning Trees | SPOJ | 4 | ||
| 33 | Closest distance | SPOJ | 4 | ||
| 34 | Lomsat gelral | Codeforces | Educational Codeforces Round 2 | 4 | |
| 35 | Tree Requests | Codeforces | Codeforces Round #316 (Div. 2) | 4 | |
| 36 | A and B and Lecture Rooms | Codeforces | Codeforces Round #294 (Div. 2) | 4 | |
| 37 | New Year Santa Network | Codeforces | Good Bye 2014 | 4 | |
| 38 | Design Tutorial: Inverse the Problem | Codeforces | Codeforces Round #270 | 4 | |
| 39 | Appleman and Tree | Codeforces | Codeforces Round #263 (Div. 1) & Codeforces Round #263 (Div. 2) | 4 | |
| 40 | A Lot of Games | Codeforces | Codeforces Round #260 (Div. 1) & Codeforces Round #260 (Div. 2) | 4 | |
| 41 | Propagating tree | Codeforces | Codeforces Round #225 (Div. 1) & Codeforces Round #225 (Div. 2) | 4 | |
| 42 | Vessels | Codeforces | Codeforces Round #218 (Div. 2) | 4 | |
| 43 | Xenia and Tree | Codeforces | Codeforces Round #199 (Div. 2) | 4 | |
| 44 | Book of Evil | Codeforces | Codeforces Round #196 (Div. 2) & Codeforces Round #196 (Div. 1) | 4 | |
| 45 | Ciel the Commander | Codeforces | Codeforces Round #190 (Div. 1) & Codeforces Round #190 (Div. 2) | 4 | |
| 46 | Zero Tree | Codeforces | Codeforces Round #168 (Div. 1) & Codeforces Round #168 (Div. 2) | 4 | |
| 47 | Enemy is weak | Codeforces | Codeforces Beta Round #57 (Div. 2) | 4 | |
| 48 | Tree Construction | Codeforces | Codeforces Round #353 (Div. 2) | 4 | |
| 49 | Connecting Universities | Codeforces | Codeforces Round #364 (Div. 1) & Codeforces Round #364 (Div. 2) | 4 | |
| 50 | Alyona and a tree | Codeforces | Codeforces Round #381 (Div. 1) & Codeforces Round #381 (Div. 2) | 4 | |
| 51 | Chloe and pleasant prizes | Codeforces | Codeforces Round #384 (Div. 2) | 4 | |
| 52 | Ilya And The Tree | Codeforces | Codeforces Round #430 (Div. 2) | 4 | |
| 53 | Garland | Codeforces | Codeforces Round #398 (Div. 2) | 4 | |
| 54 | Blood Cousins | Codeforces | Codeforces Round #130 (Div. 2) | 5 | |
| 55 | Spiders | Codeforces | School Regional Team Contest, Saratov, 2011 | 5 | |
| 56 | Petr# | Codeforces | Codeforces Beta Round #86 (Div. 1 Only) & Codeforces Beta Round #86 (Div. 2 Only) | 5 | |
| 57 | Lucky Tree | Codeforces | Codeforces Beta Round #84 (Div. 1 Only) & Codeforces Beta Round #84 (Div. 2 Only) | 5 | |
| 58 | Two Paths | Codeforces | Codeforces Beta Round #14 (Div. 2) | 5 | |
| 59 | Exposition | Codeforces | Codeforces Beta Round #6 (Div. 2 Only) | 5 | |
| 60 | Running Track | Codeforces | Codeforces Round #338 (Div. 2) | 5 | |
| 61 | Minimum spanning tree for each edge | Codeforces | Educational Codeforces Round 3 | 5 | |
| 62 | Super M | Codeforces | Codeforces Round #328 (Div. 2) | 5 | |
| 63 | Duff in the Army | Codeforces | Codeforces Round #326 (Div. 1) & Codeforces Round #326 (Div. 2) | 5 | |
| 64 | Valid Sets | Codeforces | Codeforces Round #277 (Div. 2) | 5 | |
| 65 | Pillars | Codeforces | Codeforces Round #271 (Div. 2) | 5 | |
| 66 | 4-point polyline | Codeforces | MemSQL Start[c]UP 2.0 - Round 1 | 5 | |
| 67 | Dungeons and Candies | Codeforces | Zepto Code Rush 2014 | 5 | |
| 68 | Tree and Queries | Codeforces | Codeforces Round #221 (Div. 1) | 5 | |
| 69 | Water Tree | Codeforces | Codeforces Round #200 (Div. 1) | 5 | |
| 70 | Sausage Maximization | Codeforces | Codeforces Round #173 (Div. 2) | 5 | |
| 71 | Cutting Figure | Codeforces | Codeforces Round #122 (Div. 1) & Codeforces Round #122 (Div. 2) | 5 | |
| 72 | Kay and Snowflake | Codeforces | Codeforces Round #359 (Div. 1) & Codeforces Round #359 (Div. 2) | 5 | |
| 73 | Misha, Grisha and Underground | Codeforces | Codeforces Round #425 (Div. 2) | 5 | |
| 74 | An overnight dance in discotheque | Codeforces | Codeforces Round #418 (Div. 2) | 5 | |
| 75 | Count on a Treap | CodeChef | 5 | ||
| 76 | Vasya and a Tree | Codeforces | Educational Codeforces Round 54 (Rated for Div. 2) | 5 | |
| 77 | Ant on the Tree | Codeforces | Codeforces Beta Round #29 (Div. 2, Codeforces format) | 6 | |
| 78 | Ants in Leaves | Codeforces | Educational Codeforces Round 7 | 6 | |
| 79 | Hamiltonian Spanning Tree | Codeforces | Wunder Fund Round 2016 (Div. 1 + Div. 2 combined) | 6 | |
| 80 | Invariance of Tree | Codeforces | Codeforces Round #319 (Div. 1) & Codeforces Round #319 (Div. 2) | 6 | |
| 81 | Road Improvement | Codeforces | Codeforces Round #302 (Div. 1) | 6 | |
| 82 | Infinite Inversions | Codeforces | Codeforces Round #301 (Div. 2) | 6 | |
| 83 | Demiurges Play Again | Codeforces | Codeforces Round #300 | 6 | |
| 84 | Work Group | Codeforces | VK Cup 2015 - Round 2 (unofficial online mirror, Div. 1 only) | 6 | |
| 85 | Information Graph | Codeforces | Codeforces Round #266 (Div. 2) | 6 | |
| 86 | Caisa and Tree | Codeforces | Codeforces Round #264 (Div. 2) | 6 | |
| 87 | On Changing Tree | Codeforces | Codeforces Round #232 (Div. 1) & Codeforces Round #232 (Div. 2) | 6 | |
| 88 | New Year Tree | Codeforces | Good Bye 2013 | 6 | |
| 89 | Apple Tree | Codeforces | Codeforces Round #202 (Div. 1) & Codeforces Round #202 (Div. 2) | 6 | |
| 90 | WTF? | Codeforces | April Fools Day Contest 2013 | 6 | |
| 91 | Game on Tree | Codeforces | Codeforces Round #172 (Div. 1) & Codeforces Round #172 (Div. 2) | 6 | |
| 92 | Gifts by the List | Codeforces | Codeforces Round #357 (Div. 2) | 6 | |
| 93 | Avoiding a disaster | A2 Online Judge | 6 | ||
| 94 | Karen and Supermarket | Codeforces | Codeforces Round #419 (Div. 1) & Codeforces Round #419 (Div. 2) | 6 | |
| 95 | Mahmoud and a xor trip | Codeforces | Codeforces Round #396 (Div. 2) | 6 | |
| 96 | Little Elephant and Tree | Codeforces | Codeforces Round #157 (Div. 1) | 7 | |
| 97 | Blood Cousins Return | Codeforces | Codeforces Round #151 (Div. 2) | 7 | |
| 98 | World Eater Brothers | Codeforces | Codeforces Round #148 (Div. 1) & Codeforces Round #148 (Div. 2) | 7 | |
| 99 | Cactus | Codeforces | Codeforces Round #143 (Div. 2) | 7 | |
| 100 | Paint Tree | Codeforces | Codeforces Round #124 (Div. 1) & Codeforces Round #124 (Div. 2) | 7 | |
| 101 | Beard Graph | Codeforces | Codeforces Round #112 (Div. 2) | 7 | |
| 102 | Beavermuncher-0xFF | Codeforces | Codeforces Beta Round #69 (Div. 1 Only) & Codeforces Beta Round #69 (Div. 2 Only) | 7 | |
| 103 | Gift | Codeforces | All-Ukrainian School Olympiad in Informatics | 7 | |
| 104 | Pursuit For Artifacts | Codeforces | Educational Codeforces Round 10 | 7 | |
| 105 | Road Improvement | Codeforces | VK Cup 2016 - Qualification Round 2 | 7 | |
| 106 | Famil Door and Roads | Codeforces | Codeforces Round #343 (Div. 2) | 7 | |
| 107 | Acyclic Organic Compounds | Codeforces | Codeforces Round #333 (Div. 1) | 7 | |
| 108 | Happy Tree Party | Codeforces | Codeforces Round #329 (Div. 2) | 7 | |
| 109 | Bribes | Codeforces | Bubble Cup 8 - Finals [Online Mirror] | 7 | |
| 110 | Bear and Drawing | Codeforces | Codeforces Round #318 [RussianCodeCup Thanks-Round] (Div. 1) & Codeforces Round #318 [RussianCodeCup Thanks-Round] (Div. 2) | 7 | |
| 111 | Ann and Half-Palindrome | Codeforces | Codeforces Round #311 (Div. 2) | 7 | |
| 112 | Case of Computer Network | Codeforces | Codeforces Round #310 (Div. 1) | 7 | |
| 113 | Treeland Tour | Codeforces | Codeforces Round #279 (Div. 2) | 7 | |
| 114 | Guess the Tree | Codeforces | Codeforces Round #245 (Div. 1) & Codeforces Round #245 (Div. 2) | 7 | |
| 115 | Hill Climbing | Codeforces | Codeforces Round #238 (Div. 1) | 7 | |
| 116 | Ksenia and Pawns | Codeforces | Codeforces Round #224 (Div. 2) | 7 | |
| 117 | Inna and Sequence | Codeforces | Codeforces Round #220 (Div. 2) | 7 | |
| 118 | Divisor Tree | Codeforces | Codeforces Round #196 (Div. 2) & Codeforces Round #196 (Div. 1) | 7 | |
| 119 | Little Girl and Problem on Trees | Codeforces | Codeforces Round #169 (Div. 2) | 7 | |
| 120 | Black and White Tree | Codeforces | Codeforces Round #158 (Div. 2) | 7 | |
| 121 | Big Maximum Sum | Codeforces | Codeforces Beta Round #67 (Div. 2) | 7 | |
| 122 | Old Berland Language | Codeforces | Codeforces Beta Round #37 | 7 | |
| 123 | Iahub and Xors | Codeforces | Codeforces Round #198 (Div. 1) | 7 | |
| 124 | New Roads | Codeforces | Codeforces Round #386 (Div. 2) | 7 | |
| 125 | Peterson Polyglot | Codeforces | Codeforces Round #402 (Div. 1) & Codeforces Round #402 (Div. 2) | 7 | |
| 126 | Ralph And His Tour in Binary Country | Codeforces | Codeforces Round #447 (Div. 2) | 7 | |
| 127 | Tree | A2 Online Judge | 7 | ||
| 128 | IT Restaurants | Codeforces | VK Cup 2012 Finals (unofficial online-version) | 8 | |
| 129 | Archaeology | Codeforces | Croc Champ 2012 - Round 2 | 8 | |
| 130 | e-Government | Codeforces | VK Cup 2012 Round 2 | 8 | |
| 131 | Castle | Codeforces | Codeforces Beta Round #79 (Div. 1 Only) | 8 | |
| 132 | Beautiful Road | Codeforces | Codeforces Beta Round #73 (Div. 1 Only) | 8 | |
| 133 | Genetic engineering | Codeforces | Yandex.Algorithm 2011 Round 2 | 8 | |
| 134 | Petya and Tree | Codeforces | Yandex.Algorithm 2011 Round 1 | 8 | |
| 135 | Scheme | Codeforces | Codeforces Beta Round #22 (Div. 2 Only) | 8 | |
| 136 | The Chocolate Spree | Codeforces | Manthan, Codefest 16 | 8 | |
| 137 | Magic Matrix | Codeforces | Educational Codeforces Round 9 | 8 | |
| 138 | Preorder Test | Codeforces | 8VC Venture Cup 2016 - Final Round | 8 | |
| 139 | Kingdom and its Cities | Codeforces | Codeforces Round #339 (Div. 1) | 8 | |
| 140 | Zublicanes and Mumocrates | Codeforces | Codeforces Round #322 (Div. 2) | 8 | |
| 141 | Matching Names | Codeforces | VK Cup 2015 - Finals, online mirror | 8 | |
| 142 | Drazil and Morning Exercise | Codeforces | Codeforces Round #292 (Div. 1) | 8 | |
| 143 | Birthday | Codeforces | Codeforces Round #282 (Div. 1) | 8 | |
| 144 | Tourists | Codeforces | Codeforces Round #278 (Div. 1) | 8 | |
| 145 | DZY Loves Planting | Codeforces | Codeforces Round #254 (Div. 1) | 8 | |
| 146 | Adam and Tree | Codeforces | Codeforces Round #253 (Div. 1) | 8 | |
| 147 | Choosing Subtree is Fun | Codeforces | Codeforces Round #219 (Div. 1) | 8 | |
| 148 | Balance | Codeforces | Codeforces Round #188 (Div. 1) & Codeforces Round #188 (Div. 2) | 8 | |
| 149 | Shaass the Great | Codeforces | Codeforces Round #178 (Div. 2) | 8 | |
| 150 | Close Vertices | Codeforces | Croc Champ 2013 - Round 2 | 8 | |
| 151 | Polo the Penguin and Trees | Codeforces | Codeforces Round #177 (Div. 1) | 8 | |
| 152 | Thwarting Demonstrations | Codeforces | Codeforces Round #121 (Div. 1) | 8 | |
| 153 | Arpa’s letter-marked tree and Mehrdad’s Dokhtar-kosh paths | Codeforces | Codeforces Round #383 (Div. 1) | 8 | |
| 154 | Noble Knight's Path | Codeforces | Codeforces Round #140 (Div. 1) | 9 | |
| 155 | Alien DNA | Codeforces | Codeforces Round #134 (Div. 1) | 9 | |
| 156 | Garden | Codeforces | Codeforces Round #108 (Div. 2) | 9 | |
| 157 | Freezing with Style | Codeforces | Codeforces Round #107 (Div. 1) | 9 | |
| 158 | Pairs | Codeforces | Yandex.Algorithm Open 2011 Qualification 1 | 9 | |
| 159 | Information Reform | Codeforces | Codeforces Beta Round #64 | 9 | |
| 160 | Caterpillar | Codeforces | Codeforces Beta Round #48 | 9 | |
| 161 | Clockwork Bomb | Codeforces | Codeforces Round #345 (Div. 1) | 9 | |
| 162 | Pastoral Oddities | Codeforces | Codeforces Round #334 (Div. 1) | 9 | |
| 163 | Tavas on the Path | Codeforces | Codeforces Round #299 (Div. 1) | 9 | |
| 164 | Fox And Travelling | Codeforces | Codeforces Round #290 (Div. 1) | 9 | |
| 165 | Random Function and Tree | Codeforces | Codeforces Round #275 (Div. 1) | 9 | |
| 166 | Berland Federalization | Codeforces | Testing Round #10 | 9 | |
| 167 | Big Problems for Organizers | Codeforces | RCC 2014 Warmup (Div. 1) | 9 | |
| 168 | Pilgrims | Codeforces | Codeforces Round #202 (Div. 1) | 9 | |
| 169 | Maze | Codeforces | Codeforces Beta Round #92 (Div. 1 Only) | 9 | |
| 170 | Singer House | Codeforces | Codeforces Round #424 (Div. 1, rated, based on VK Cup Finals) | 9 | |
| 171 | Arkady and a Nobody-men | Codeforces | Codeforces Round #434 (Div. 1, based on Technocup 2018 Elimination Round 1) | 9 | |
| 172 | Timofey and a flat tree | Codeforces | Codeforces Round #395 (Div. 1) | 9 | |
| 173 | Surprise me! | Codeforces | Codeforces Round #415 (Div. 1) | 9 | |
| 174 | Tree and Table | Codeforces | Codeforces Round #153 (Div. 1) | 10 | |
| 175 | Tree or not Tree | Codeforces | Codeforces Beta Round #88 | 10 | |
| 176 | Help King | Codeforces | Codeforces Beta Round #78 (Div. 1 Only) & Codeforces Beta Round #78 (Div. 2 Only) | 10 | |
| 177 | Leaders | Codeforces | Yandex.Algorithm 2011 Finals | 10 | |
| 178 | Galaxy Union | Codeforces | School Personal Contest #3 (Winter Computer School 2010/11) - Codeforces Beta Round #45 (ACM-ICPC Rules) | 10 | |
| 179 | Bear and Chemistry | Codeforces | VK Cup 2016 - Round 1 | 10 | |
| 180 | Island Puzzle | Codeforces | 8VC Venture Cup 2016 - Final Round | 10 | |
| 181 | Mirror Box | Codeforces | Codeforces Round #320 (Div. 1) [Bayan Thanks-Round] | 10 | |
| 182 | Campus | Codeforces | Codeforces Round #317 [AimFund Thanks-Round] (Div. 1) | 10 | |
| 183 | Restoring Map | Codeforces | VK Cup 2015 - Finals, online mirror | 10 | |
| 184 | Logistical Questions | Codeforces | VK Cup 2015 - Finals, online mirror | 10 | |
| 185 | Berland Miners | Codeforces | VK Cup 2015 - Round 2 (unofficial online mirror, Div. 1 only) | 10 | |
| 186 | Spiders Evil Plan | Codeforces | ZeptoLab Code Rush 2015 | 10 | |
| 187 | Misha and LCP on Tree | Codeforces | Codeforces Round #285 (Div. 1) | 10 | |
| 188 | New Year Running | Codeforces | Good Bye 2014 | 10 | |
| 189 | ELCA | Codeforces | Codeforces Round #275 (Div. 1) | 10 | |
| 190 | An easy problem about trees | Codeforces | MemSQL Start[c]UP 2.0 - Round 2 | 10 | |
| 191 | Furukawa Nagisa's Tree | Codeforces | Codeforces Round #248 (Div. 1) | 10 | |
| 192 | Escaping on Beaveractor | Codeforces | ABBYY Cup 3.0 - Finals (online version) | 10 | |
| 193 | Red-Black Cobweb | Codeforces | Codeforces Round #426 (Div. 1) | 10 | |
| 194 | ALT | Codeforces | Codeforces Round #406 (Div. 1) | 10 | |
| 195 | Sloth | Codeforces | Codeforces Round #446 (Div. 1) | 10 | |
| 196 | In a Trap | Codeforces | Codeforces Round #429 (Div. 1) | 10 | |
| 197 | Restore the Tree | Codeforces | Codeforces Round #440 (Div. 1, based on Technocup 2018 Elimination Round 2) | 10 | |
| 198 | Perpetual Motion Machine | Codeforces | Codeforces Round #424 (Div. 1, rated, based on VK Cup Finals) | 10 | |
| 199 | Rap God | Codeforces | Codeforces Round #406 (Div. 1) | 10 | |
| 200 | Iron Man | Codeforces | Codeforces Round #366 (Div. 1) | 10 | |
| 201 | Nikita and game | Codeforces | Codeforces Round #430 (Div. 2) | 10 | |
| 202 | Tree and XOR | Codeforces | Mail.Ru Cup 2018 Round 2 | 10 |