reidenong / CompetitiveProgramming

A blog documenting my journey in Competitive Programming.

Competitive Programming

A documentation of my journey in Competitive Programming.

• 📚 Code Library

• 📘 General Notes

• ✅ Problem Log

• 🏅 Contest Log

• 🚧 WIP Questions

Problem Log (AC)

Use Ctrl + F to search for questions, keywords or tags.

Listed in reverse chronological order.

TAGS : [AdHoc], [DS], [Recursion], [Math], [Greedy], [BinarySearch], [Sorting], [BitOp], [DP], [Graph], [FP]

1. kattis-blockcrusher: Grid dijkstra, Difficulty: 3.6, [Graph],

2. kattis-texassummers: Difficulty: 4.1, [Graph],

3. kattis-shortestpath2: SSSP Dijkstra, Difficulty: 3.7, [Graph],

4. kattis-flowerytrails: Dijkstra + Predecessor, Difficulty: 3.5, [Graph],

5. kattis-shortestpath1: SSSP Dijkstra, Difficulty: 3.0, [Graph],

6. kattis-knightjump: Difficulty: 2.4, [Graph],

7. kattis-hidingplaces: Difficulty: 1.7, [Graph],

8. codeforces-1974C: Difiiculty: ?, [AdHoc],

9. codeforces-1974B: Difiiculty: ?, [AdHoc],

10. codeforces-1974A: Difiiculty: ?, [AdHoc],

11. kattis-grasshopper: Knight Moves BFS, Difficulty 3.7, [Graph],

12. kattis-oceancurrents: 0-1 BFS, Difficulty 5.4, [Graph],

13. kattis-mallmania: Multi-Source BFS, Difficulty 4.9, [Graph],

14. kattis-fire2: Difficulty 4.6, [Graph],

15. kattis-lost: Difficulty 4.8, [Graph],

16. kattis-horror: Difficulty 2.9, [Graph],

17. kattis-grid: Difficulty 2.7, [Graph],

18. codeforces-1944B: Difficulty: ?, [AdHoc],

19. codeforces-1937B: Difiiculty: ?, [AdHoc],

20. codeforces-1937A: Difiiculty: ?, [AdHoc],

21. codeforces-1933E: Difficulty: ?, [AdHoc],

22. codeforces-1933D: Difficulty: ?, [AdHoc],

23. codeforces-1933C: Difiiculty: ?, [AdHoc],

24. codeforces-1933B: Difiiculty: ?, [AdHoc],

25. codeforces-1933A: Difiiculty: 1200, [AdHoc],

26. codeforces-1923C: Difficulty: ?, [AdHoc],

27. codeforces-1923B: Difiiculty: ?, [Greedy],

28. codeforces-1923A: Difiiculty: ?, [AdHoc],

29. codeforces-1928B: Difiiculty: 1200, [AdHoc],

30. codeforces-1928A: Difiiculty: 800, [AdHoc],

31. codeforces-1917C: Difficulty: 1600, [AdHoc],

32. codeforces-1925C: Difficulty: 1500, [AdHoc],

33. codeforces-1925B: Difiiculty: 1200, [AdHoc],

34. codeforces-1925A: Difiiculty: 800, [Math],

35. codeforces-1917B: Difiiculty: 1100, [AdHoc],

36. codeforces-1917A: Difiiculty: 800, [AdHoc],

37. codeforces-1920D: Difficulty: 1800, [DS],

38. codeforces-1920C: Difficulty: 1500, [Math],

39. codeforces-1922E: Difficulty: 1800, [AdHoc],

40. codeforces-1922D: Difficulty: 1900, [DS],

41. codeforces-1920B: Difiiculty: 1100, [Greedy],

42. codeforces-1920A: Difficulty: 800, [AdHoc],

43. codeforces-1922C: Difficulty: 1300, [Greedy],

44. codeforces-1922B: Difficulty: 1200, [AdHoc],

45. codeforces-1922A: Difficulty: 800, [AdHoc],

46. kattis-buttonbashing: Difficulty 3.5, [Graph][DP],

47. kattis-chatter: Java UFDS, Difficulty 4.3, [DS],

48. kattis-minspantree: Difficulty 4.5, [Graph],

49. kattis-lostmap: Difficulty 2.0, [Graph],

50. kattis-cats: Difficulty 4.1, [Graph],

51. kattis-islandhopping: MSTs with Kruskal, Difficulty 2.9, [Graph],

52. kattis-permutationdescent: Difficulty 2.1, [Recursion][DP],

53. kattis-weightofwords: Difficulty 2.9, [Ad-Hoc],

54. kattis-keyboardconcert: Difficulty 3.4, [DP],

55. kattis-haybales: Shortest code, Difficulty 5.8, [Greedy],

56. kattis-driver: Difficulty 4.0, [Greedy],

57. kattis-applesack: Difficulty 3.4, [Greedy],

58. kattis-fairdivision: Difficulty 3.6, [Greedy],

59. kattis-ceremony: Difficulty 3.6, [Greedy],

60. kattis-messages: Difficulty 5.0, [Greedy],

61. kattis-avoidland: Difficulty 3.1, [AdHoc][Greedy],

62. kattis-janeeyre: Difficulty 2.9, [DS],

63. kattis-hypercube: Difficulty 3.7, [AdHoc][BitOp],

64. kattis-bard: Difficulty 2.9, [DS],

65. kattis-backspace: Difficulty 2.4, [AdHoc][DS],

66. kattis-reversebinary: Difficulty 1.4, [AdHoc][DS],

67. kattis-generalizedrecursivefunctions: Difficulty 4.6, [AdHoc],

68. kattis-threepowers: Difficulty 2.4, [AdHoc],

69. kattis-ultraquicksort: Difficulty 5.2, [Sorting][AdHoc],

70. kattis-sort: Difficulty 2.8, [Sorting][AdHoc],

71. kattis-includescoring: Difficulty 5.7, [Sorting][AdHoc],

72. kattis-longswaps: Difficulty 3.7, [Sorting][AdHoc],

73. kattis-chartingprogress: Difficulty 1.7, [AdHoc],

74. kattis-froshweek: MergeSort in Java, Difficulty 4.4, [AdHoc][Sorting],

75. kattis-addemup: Difficulty 5.2, [AdHoc][DS],

76. kattis-astro: Difficulty 3.9, [AdHoc],

77. kattis-erase: Difficulty 1.7, [AdHoc],

78. kattis-rankproblem: Difficulty 2.8, [AdHoc],

79. kattis-falcondive: Difficulty 3.6, [AdHoc],

80. kattis-bokhyllor: Difficulty 3.3, [AdHoc],

81. kattis-babypanda: Difficulty 2.3, [AdHoc],

82. kattis-coffeecupcombo: Difficulty 1.7, [AdHoc],

83. kattis-sifferprodukt: Difficulty 1.6, [AdHoc],

84. kattis-electionparadox: Difficulty 1.9, [AdHoc],

85. kattis-undeadoralive: Difficulty 1.5, [AdHoc],

86. kattis-internationaldates: Difficulty 1.3, [AdHoc],

87. kattis-addingtrouble: Difficulty 1.3, [AdHoc],

88. kattis-codetosavelives: Java String to char Stream, Difficulty 1.7, [FP],

89. kattis-metronome: Difficulty 1.2, [AdHoc],

90. kattis-faultyrobot: Difficulty 4.1, [Graph],

91. kattis-equivalences: SCCs, Kosaraju's Algorithm, Difficulty 6.4, [Graph],

92. kattis-dominos: SCCs, Kosaraju's Algorithm, Difficulty 4.0, [Graph],

93. kattis-cantinaofbabel: SCC, Kosaraju, Difficulty 3.0, [Graph],

94. kattis-caveexploration: Bridges DFS, Difficulty 3.6, [Graph],

95. kattis-birthday: Articulation points and Bridges DFS, Difficulty 3.1, [Graph],

96. kattis-torn2pieces: Difficulty 3.1, [Graph],

97. kattis-molekule: DFS bipartite check, Difficulty 3.5, [Graph],

98. kattis-hoppers: DFS bipartite check, DFS CCs, Difficulty 3.9, [Graph],

99. kattis-pickupsticks: DFS cyclecheck, DFS toposort, Difficulty 4.8, [Graph],

100. kattis-runningmom: DFS cyclecheck with memoization, Difficulty 3.6, [Graph][DP],

101. kattis-conservation: Modified Kahn's Algorithm, Difficulty 4.8, [Graph],

102. kattis-brexit: BFS, Difficulty 3.0, [Graph],

103. kattis-builddeps: DFS Toposort, Difficulty 4.1, [Graph],

104. kattis-islands3: Difficulty 1.8, [Graph],

105. kattis-coast: Flood Fill, Difficulty 3.6, [Graph],

106. kattis-10kindsofpeople: Flood Fill with Memoization, Difficulty 5.3, [Graph],

107. kattis-gold: Flood Fill, Difficulty 2.4, [Graph],

108. kattis-countingstars: Flood Fill, Difficulty 3.0, [Graph],

109. kattis-amoebas: Flood Fill, Difficulty 2.0, [Graph],

110. kattis-terraces: Flood Fill, Difficulty 3.6, [Graph],

111. kattis-reachableroads: Difficulty 2.2, [Graph],

112. kattis-dominoes2: Difficulty 3.5, [Graph],

113. kattis-wheresmyinternet: Difficulty 2.9, [Graph],

114. kattis-supercomputer: RSQ, fenwick, Difficulty 3.3, [DS],

115. kattis-moviecollection: RSQ Fenwick Tree, Difficulty 4.8, [DS],

116. kattis-justforsidekicks: RSQ Fenwick Tree, Difficulty 3.8, [DS],

117. kattis-fenwick: RSQ Fenwick Tree, Difficulty 4.8, [DS],

118. kattis-ladice: UFDS, Difficulty 3.8, [DS],

119. kattis-control: UFDS, Difficulty 4.2, [DS],

120. kattis-unionfind: UFDS, Difficulty 4.5, [DS],

121. kattis-walrusweights: Difficulty 3.4, [DP],

122. kattis-tight: Difficulty 3.2, [DP],

123. kattis-kutevi: Difficulty 2.6, [DP],

124. kattis-ticketpricing: Difficulty 4.6, [DP],

125. kattis-spiderman: Difficulty 4.6, [DP],

126. kattis-nikola: Difficulty 3.7, [DP],

127. kattis-exactchange2: coin change, Difficulty 3.8, [DP],

128. kattis-canonical: coin change, Difficulty 4.7, [DP],

129. kattis-bagoftiles: Knapsack variant, Difficulty 6.2, [DP],

130. kattis-orders: Coin Change Variant, Difficulty 5.4, [DP],

131. kattis-presidentialelections: 0-1 Knapsack Variant, Difficulty 4.8, [DP],

132. kattis-knapsack: Classic 0-1 Knapsack, Difficulty 4.9, [DP],

133. kattis-trainsorting: LIS/LDS with anchor, Difficulty 6.5, [DP],

134. kattis-nesteddolls: LIS, Dilworth's Theorem, Difficulty 6.7, [DP],

135. kattis-increasingsubsequence: O(N log K) LIS, Difficulty 4.1, [DP],

136. kattis-sellingspatulas: 1D Max RangeSum, Kadane, Difficulty 7.3, [DP],

137. kattis-prozor: 2D Fixed RangeSum, Difficulty 1.8, [AdHoc],

138. kattis-commercials: 1-D Max RangeSum, Kadane, Difficulty 1.8, [DP],

139. kattis-virus: Difficulty 3.5, [AdHoc],

140. kattis-stockbroker: Difficulty 3.3, [Greedy],

141. kattis-dvds: Difficulty 2.9, [AdHoc],

142. kattis-bank: Difficulty 2.8, [Greedy][DS],

143. kattis-ants: Difficulty 2.3, [AdHoc],

144. kattis-workstations: Difficulty 3.4, [Greedy][DS],

145. kattis-vegetables: Difficulty 3.3, [Greedy],

146. kattis-canvas: Difficulty 3.5, [Greedy][DS],

147. kattis-ballotboxes: Difficulty 4.3, [Greedy][DS],

148. kattis-delivery: Difficulty 2.9, [Greedy],

149. kattis-birds: Difficulty 3.6, [AdHoc],

150. kattis-airconditioned: Interval Scheduling problem, Difficulty 3.4, [Greedy],

151. kattis-color: Difficulty 2.5, [Greedy],

152. kattis-shopaholic: Difficulty 2.2, [Greedy],

153. kattis-minimumscalar: Difficulty 2.2, [Greedy],

154. kattis-icpcteamselection: Difficulty 3.3, [Greedy],

155. kattis-squarepegs: Difficulty 2.7, [Greedy],

156. kattis-froshweek2: Difficulty 2.2, [Greedy],

157. kattis-ceiling: PY Binary Search Tree, Difficulty 2.2, [DS],

158. kattis-a1paper: Difficulty 3.9, [Greedy][Math],

159. kattis-suspensionbridges: PY BSTA, Difficulty 3.0, [BinarySearch][Math],

160. kattis-monk: PY BSTA, Difficulty 3.3, [BinarySearch],

161. kattis-freeweights: CPP BSTA, Difficulty 4.3, [BinarySearch],

162. kattis-carefulascent: PY BSTA, Difficulty 2.1, [BinarySearch],

163. kattis-roompainting: Difficulty 3.7, [BinarySearch],

164. kattis-outofsorts: PY Binary search, Difficulty 2.9, [BinarySearch],

165. kattis-firefly: PY Binary search bisect, Difficulty 3.3, [BinarySearch],

166. kattis-pagelayout: Combinatoric Recursive backtracking, Difficulty 5.4, [Recursion],

167. kattis-fruitbaskets: Combinative Recursive backtracking, Difficulty 4.5, [Recursion],

168. kattis-dobra: Permutative Recursive backtracking, Difficulty 3.6, [Recursion],

169. kattis-paintings: Permutative Recursive backtracking, Difficulty 4.0, [Recursion],

170. kattis-natjecanje: Difficulty 2.3, [AdHoc],

171. kattis-goodmorning: Difficulty 2.8, [AdHoc],

172. kattis-toys: general case Josephus problem, Difficulty 4.0, [Math],

173. kattis-musicalchairs: Difficulty 3.6, [AdHoc],

174. kattis-eenymeeny: Difficulty 1.8, [AdHoc],

175. kattis-thanosthehero: Difficulty 3.7, [Math],

176. kattis-falling: Prime factorization, Difficulty 4.0, [Math],

177. kattis-crackingrsa: Sieve of Eratosthenes, Difficulty 2.1, [Math],

178. kattis-videospeedup: Difficulty 1.8, [Math],

179. kattis-trollhunt: Difficulty 2.4, [Math],

180. kattis-growlinggears: Difficulty 2.0, [Math],

181. kattis-easiest: Difficulty 1.6, [AdHoc],

182. kattis-walls: Difficulty 4.3, [AdHoc],

183. kattis-islands: Difficulty 3.0, [AdHoc],

184. kattis-communication: Difficulty 2.1, [BitOp],

185. kattis-flexible: Difficulty 1.8, [AdHoc],

186. kattis-zagrade: Difficulty 3.3, [AdHoc],

187. kattis-squaredeal: Difficulty 3.9, [AdHoc],

188. kattis-geppetto: CPP Bitmasking permutations, Difficulty 2.6, [BitOp],

189. kattis-veci: Difficulty 1.9, [AdHoc],

190. kattis-dreamer: Python datetime, Difficulty 2.2, [AdHoc],

191. kattis-dancerecital: CPP Bitmasking, Permutations of int array, Difficulty 3.5, [BitOp],

192. kattis-tautology: Difficulty 3.0, [AdHoc],

193. kattis-lektira: Difficulty 2.9, [AdHoc],

194. kattis-calculatingdartscores: Difficulty 3.0, [AdHoc],

195. kattis-cudoviste: Difficulty 1.4, [AdHoc],

196. kattis-golombrulers: Difficulty 3.1, [AdHoc],

197. kattis-closestsums: Difficulty 2.4, [AdHoc],

198. kattis-blackfriday: Difficulty 2.4, [AdHoc],

199. kattis-pet: Difficulty 1.4, [AdHoc],

200. kattis-cardtrick2: Difficulty 1.8, [AdHoc],

201. kattis-gcpc: CPP OST pbds, Difficulty 4.5, [DS],

202. kattis-cookieselection: CPP OST pbds, Difficulty 4.9, [DS],

203. kattis-continuousmedian: CPP OST pbds of pairs, Difficulty 3.4, [DS],

204. kattis-babynames: Dynamic Ranking, CPP OST pbds, Difficulty 6.1, [DS],

205. kattis-srednji: Difficulty 4.0, [DS],

206. kattis-kattissquest: CPP map of priority queues, Difficulty 3.4, [DS],

207. kattis-administrativeproblems: Difficulty 6.1, [DS],

208. kattis-compoundwords: Difficulty 1.8, [DS],

209. kattis-candydivision: Difficulty 4.0, [DS],

210. kattis-bst: not a real bst, Difficulty 6.9, [DS],

211. kattis-awkwardparty: CPP unordered map of vectors, Difficulty 3.0, [DS],

212. kattis-addingwords: Difficulty 4.0, [DS],

213. kattis-conversationlog: Difficulty 2.9, [DS],

214. kattis-grandpabernie: CPP unordered map of vectors, Difficulty 3.2, [DS],

215. kattis-recount: Difficulty 2.1, [DS],

216. kattis-esej: Difficulty 2.4, [DS],

217. kattis-greetingcard: CPP set of pairs, Difficulty 4.4, [DS],

218. kattis-esej: Difficulty 3.2, [AdHoc],

219. kattis-cd: CPP unordered set, Difficulty 4.6, [DS],

220. kattis-freefood: Difficulty 1.6, [AdHoc],

221. kattis-busnumbers: Difficulty 2.6, [AdHoc],

222. kattis-bookingaroom: Difficulty 1.4, [AdHoc],

223. kattis-quickbrownfox: Py alphabet list, Difficulty 1.8, [AdHoc],

224. kattis-alphabetspam: Difficulty 1.4, [AdHoc],

225. kattis-jugglingpatterns: C++ STL Priority Queue, Difficulty 5.9, [DS],

226. kattis-knigsoftheforest: Py HeapQ Priority Q, Difficulty 4.2, [DS],

227. kattis-stockprices: Py HeapQ Priority Q, Difficulty 4.1, [DS],

228. kattis-numbertree: Difficulty 2.1, [AdHoc],

229. kattis-teque: cpp STL deque, difficulty 3.6, [DS],

230. kattis-sim: Difficulty 3.8, [DS],

231. kattis-joinstrings: Iterative DFS, Difficulty 4.8, [Graph],

232. kattis-integerlists: cpp STL deque, difficulty 5.4, [DS],

233. kattis-delimitersoup: Difficulty 2.1, [AdHoc],

234. kattis-circuitmath: Python alphabet lookup table, Difficulty 2.1, [AdHoc][DS],

235. kattis-bungeebuilder: Python list stack, Difficulty 3.3, [AdHoc][DS],

236. kattis-throwns: Java STL Stack, Difficulty 2.7, [DS],

237. kattis-restaurant: Difficulty 4.2, [AdHoc],

238. kattis-pairingsocks: python deque stack, Difficulty 2.7, [DS],

239. kattis-evenup: cpp STL Stack, difficulty 2.6, [Bitwise],

240. kattis-wizardofodds: Difficulty 2.7, [DS],

241. kattis-simpleaddition: Difficulty 2.2, [AdHoc],

242. kattis-primaryarithmetic: Java Strings, Difficulty 2.5, [AdHoc],

243. kattis-snapperhard/snappereasy: Bitwise simulation, difficulty 2.7, [Bitwise],

244. kattis-deathstar: simultaneous bitwise equations, difficulty 1.8, [Bitwise],

245. kattis-bitbybit: Difficulty 2.9, [AdHoc],

246. kattis-mali: counting sort implementation, difficulty 6.1, [Sorting][Greedy],

247. kattis-classy: Difficulty 4.7, [Sorting],

248. kattis-musicyourway: Difficulty 2.3, [Sorting],

249. kattis-sortofsorting: Python key-lambda sort, difficulty 2.1, [Sorting],

250. kattis-sidewayssorting: Python lexographical sort, difficulty 2.3, [Sorting],

251. kattis-mjehuric: bubble sort simulation, difficulty 1.7, [Sorting],

252. kattis-height: insertion sort simulation, difficulty 2.1, [Sorting],

253. kattis-basicprogramming2: difficulty 3.5, [Sorting],

254. kattis-rings2: difficulty 4.0, [AdHoc],

255. kattis-flagquiz: difficulty 3.4, [AdHoc],

256. kattis-2048: Python Rotation of 2D List, difficulty 2.8, [DS],

257. kattis-nineknights: difficulty 2.3, [AdHoc],

258. kattis-flowshop: pattern recognition, difficulty 2.4, [AdHoc],

259. kattis-epigdanceoff: Java 2d input, difficulty 2.1, [DS],

260. kattis-pivot: Java Stacks, difficulty 2.5, [DS],

261. kattis-mastermind: Java Strings/Characters exercise, difficulty 2.7, [AdHoc],

262. kattis-divideby100: difficulty 3.9, [AdHoc],

263. kattis-greedilyincreasing: Java arrayList manipulation, difficulty 2.1, [DS],

264. kattis-baloni: difficulty 3.0, [AdHoc],

265. kattis-jollyjumpers: Java Input/Output, difficulty 3.2, [DS],

266. kattis-functionalfun: reading python EOF, difficulty 1.9, [AdHoc],

267. kattis-froggie: difficulty 6.1, [AdHoc],

268. kattis-skener: difficulty 1.6, [AdHoc],

269. kattis-nsum: Difficulty 1.3, [FP],

270. kattis-timebomb: difficulty 1.8, [AdHoc],

271. kattis-secretmessage: difficulty 1.8, [AdHoc],

272. kattis-conundrum: difficulty 1.4, [AdHoc],

273. kattis-rimski: difficulty 4.0, [AdHoc],

274. kattis-birthdayboy: difficulty 4.5, [AdHoc],

275. kattis-bestbefore: python date time, list permutations, difficulty 3.7, [AdHoc],

276. kattis-friday: difficulty 2, [AdHoc],

277. kattis-creditcard: difficulty 5.4, [AdHoc],

278. kattis-beatspread: difficulty 2.4, [AdHoc],

279. kattis-chopin: python string input, difficulty 1.8, [AdHoc],

280. kattis-turtlemaster: use of pair<int,int> function, difficulty 2.8, [AdHoc],

281. kattis-tictactoe2: difficulty 5.2, [AdHoc],

282. kattis-battleship: difficulty 4.5, [AdHoc],

283. kattis-trik: difficulty 1.5, [AdHoc],

284. kattis-guessinggame: cin ignore for getline, difficulty 3.1, [AdHoc],

285. kattis-gamerank: difficulty 3.6, [AdHoc],

286. kattis-connectthedots: ASCII keys, Array of int pairs, difficulty 3.7, [AdHoc],

287. kattis-chess: Python Set intersection, difficulty 2.9, [AdHoc],

288. kattis-memorymatch: Set of <string, int> pairs, difficulty 4.1, [DS][AdHoc],

289. kattis-shuffling: difficulty 2.5, [AdHoc],

290. kattis-bela: difficulty 1.4, [AdHoc],

Contest Log

Tags: [Virtual], [Rated]

1. CodeForces 1944 Div2 [R]

2. CodeForces 1937 Div2 [R]

3. CodeForces 1933 Div3 [R]

4. CodeForces 1923 Div2 [R]

5. CodeForces 1928 Div2 [R]

6. CodeForces 1925 Div2 [R]

7. CodeForces 1917 Div2 [V]

8. CodeForces 1920 Div2 [V]

9. CodeForces 1922 Div2 [R]

Unsolved / WIP Questions

• kattis-windows: window simulation, trick is to simulate wrt window and not space
• kattis-bread: sorting question through operation abc --> cab (rotation of subsequence 3)
• kattis-magicsequence: radix sort in custom base. will come back when more familiar with bitwise operations
• kattis-longestcommonsubsequence
• kattis-almostunionfind

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