Problem Name | Online Judge | Year | Contest | Difficulty Level | |
---|---|---|---|---|---|

1 | Prime Number Theorem | SPOJ | 1 | ||

2 | Divisors | SPOJ | 1 | ||

3 | Euler Totient Function | SPOJ | 1 | ||

4 | Factorial | SPOJ | 1 | ||

5 | Game of Lines | SPOJ | 1 | ||

6 | Marbles | SPOJ | 1 | ||

7 | The Moronic Cowmpouter | SPOJ | 1 | ||

8 | Prime or Not | SPOJ | 1 | ||

9 | Prime Generator | SPOJ | 1 | ||

10 | Two squares or not two squares | SPOJ | 1 | ||

11 | Divisor Summation | SPOJ | 1 | ||

12 | Integer Factorization (15 digits) | SPOJ | 1 | ||

13 | LCM Sum | SPOJ | 1 | ||

14 | GCD Extreme | SPOJ | 1 | ||

15 | T-primes | Codeforces | Codeforces Round #142 (Div. 2) | 1 | |

16 | Hexadecimal's theorem | Codeforces | Codeforces Round #125 (Div. 2) | 1 | |

17 | Lucky Division | Codeforces | Codeforces Beta Round #91 (Div. 2 Only) | 1 | |

18 | Panoramix's Prediction | Codeforces | Codeforces Beta Round #69 (Div. 2 Only) | 1 | |

19 | Almost Prime | Codeforces | Codeforces Beta Round #26 (Codeforces format) | 1 | |

20 | Medium Factorization | SPOJ | 1 | ||

21 | Cifera | Codeforces | Codeforces Beta Round #86 (Div. 2 Only) | 1 | |

22 | The Equation | SGU | 1 | ||

23 | Prime Cuts | UVA | 1 | ||

24 | Goldbach's Conjecture | UVA | 1 | ||

25 | Goldbach's Conjecture (II) | UVA | 1 | ||

26 | Simply Emirp | UVA | 1 | ||

27 | Twin Primes | UVA | 1 | ||

28 | Prime Words | UVA | 1 | ||

29 | The primary problem | UVA | 1 | ||

30 | Ones | UVA | 1 | ||

31 | Relatives | UVA | 1 | ||

32 | Graph Connectivity | UVA | 1 | ||

33 | Count the factors | TJU | 1 | ||

34 | Tip Top Game | SPOJ | 1 | ||

35 | Factovisors | UVA | 1 | ||

36 | Play with Floor and Ceil | UVA | 1 | ||

37 | Totient Extreme | SPOJ | 1 | ||

38 | Factors and Factorials | UVA | 1 | ||

39 | Fombinatorial | CodeChef | 1 | ||

40 | Celebrity jeopardy | UVA | 1 | ||

41 | Again Twenty Five! | Codeforces | Experimental Educational Round: VolBIT Formulas Blitz | 1 | |

42 | Multiplication Table | Codeforces | Codeforces Round #319 (Div. 2) | 1 | |

43 | Vasya and Petya's Game | Codeforces | Codeforces Round #319 (Div. 1) & Codeforces Round #319 (Div. 2) | 1 | |

44 | Bear and Poker | Codeforces | Codeforces Round #318 [RussianCodeCup Thanks-Round] (Div. 1) & Codeforces Round #318 [RussianCodeCup Thanks-Round] (Div. 2) | 1 | |

45 | A and B and Team Training | Codeforces | Codeforces Round #294 (Div. 2) | 1 | |

46 | Design Tutorial: Learn from Math | Codeforces | Codeforces Round #270 | 1 | |

47 | Fedya and Maths | Codeforces | Codeforces Round #260 (Div. 2) | 1 | |

48 | Ilya and Bank Account | Codeforces | Codeforces Round #186 (Div. 2) | 1 | |

49 | Toy Army | Codeforces | Codeforces Beta Round #72 (Div. 2 Only) | 1 | |

50 | Alyona and Numbers | Codeforces | Codeforces Round #358 (Div. 2) | 1 | |

51 | Almost Prime Numbers | UVA | 1 | ||

52 | Bachgold Problem | Codeforces | Codeforces Round #388 (Div. 2) | 1 | |

53 | Arpa’s hard exam and Mehrdad’s naive cheat | Codeforces | Codeforces Round #383 (Div. 2) | 1 | |

54 | Factorial | Live Archive | 2000 | Europe - Central | 1 |

55 | String Task | Codeforces | Codeforces Beta Round #89 (Div. 2) | 1 | |

56 | The Bytelandian Cryptographer (Act I) | SPOJ | 2 | ||

57 | Sort fractions | SPOJ | 2 | ||

58 | Prime Again | SPOJ | 2 | ||

59 | Primitive Root | SPOJ | 2 | ||

60 | Divisor Summation (Hard) | SPOJ | 2 | ||

61 | Integer Factorization (20 digits) | SPOJ | 2 | ||

62 | Divisors 2 | SPOJ | 2 | ||

63 | N DIV PHI_N | SPOJ | 2 | ||

64 | Square-free integers | SPOJ | 2 | ||

65 | Playing with Marbles | SPOJ | 2 | ||

66 | Odd Numbers of Divisors | SPOJ | 2 | ||

67 | Equation | SPOJ | 2 | ||

68 | LCM Challenge | Codeforces | Codeforces Round #146 (Div. 1) & Codeforces Round #146 (Div. 2) | 2 | |

69 | Ice Sculptures | Codeforces | VK Cup 2012 Qualification Round 1 | 2 | |

70 | Jumping Champion | UVA | 2 | ||

71 | Goldbach and Euler | UVA | 2 | ||

72 | Marbles | UVA | 2 | ||

73 | Mint | UVA | 2 | ||

74 | Psycho | SPOJ | 2 | ||

75 | Minimum Number | SPOJ | 2 | ||

76 | Mr. Azad and his Son!!!!! | UVA | 2 | ||

77 | TEX Quotes | Live Archive | 1994 | North America - East Central NA | 2 |

78 | MCQ Exam | A2 Online Judge | 2 | ||

79 | Dima and Lisa | Codeforces | Codeforces Round #324 (Div. 2) | 2 | |

80 | Soldier and Number Game | Codeforces | Codeforces Round #304 (Div. 2) | 2 | |

81 | Drazil and His Happy Friends | Codeforces | Codeforces Round #292 (Div. 1) & Codeforces Round #292 (Div. 2) & Codeforces Round #292 (Div. 1) & Codeforces Round #292 (Div. 2) | 2 | |

82 | Mashmokh and Numbers | Codeforces | Codeforces Round #240 (Div. 1) & Codeforces Round #240 (Div. 2) | 2 | |

83 | Alice and Bob | Codeforces | Codeforces Round #201 (Div. 1) & Codeforces Round #201 (Div. 2) | 2 | |

84 | Rational Resistance | Codeforces | Codeforces Round #200 (Div. 1) & Codeforces Round #200 (Div. 2) | 2 | |

85 | Prime Matrix | Codeforces | Codeforces Round #166 (Div. 2) | 2 | |

86 | k-th divisor | Codeforces | Educational Codeforces Round 17 | 2 | |

87 | Leha and Function | Codeforces | Codeforces Round #429 (Div. 1) & Codeforces Round #429 (Div. 2) | 2 | |

88 | Taxes | Codeforces | Codeforces Round #382 (Div. 2) & Codeforces Round #382 (Div. 1) | 2 | |

89 | Pride | Codeforces | Codeforces Round #446 (Div. 1) & Codeforces Round #446 (Div. 2) | 2 | |

90 | Vladik and fractions | Codeforces | Codeforces Round #384 (Div. 2) | 2 | |

91 | Pythagorean Triples | Codeforces | Codeforces Round #368 (Div. 2) | 2 | |

92 | Arpa’s obvious problem and Mehrdad’s terrible solution | Codeforces | Codeforces Round #383 (Div. 2) | 2 | |

93 | Number Theory for Newbies | UVA | 2 | ||

94 | Anagrammatic Primes | UVA | 2 | ||

95 | GCD Determinant | SPOJ | 3 | ||

96 | Skyscraper Floors | SPOJ | 3 | ||

97 | Homework | SPOJ | 3 | ||

98 | Congruence Equation | SPOJ | 3 | ||

99 | Sky Code | SPOJ | 3 | ||

100 | Binomial Coefficients | SPOJ | 3 | ||

101 | Primes on Interval | Codeforces | Codeforces Round #147 (Div. 2) | 3 | |

102 | Easy Number Challenge | Codeforces | Codeforces Round #146 (Div. 2) | 3 | |

103 | Little Elephant and Numbers | Codeforces | Codeforces Round #136 (Div. 2) | 3 | |

104 | Win or Freeze | Codeforces | Codeforces Round #107 (Div. 1) & Codeforces Round #107 (Div. 2) | 3 | |

105 | Modified GCD | Codeforces | Codeforces Beta Round #67 (Div. 2) | 3 | |

106 | Noldbach problem | Codeforces | Codeforces Beta Round #17 | 3 | |

107 | Chef and Functions | CodeChef | 3 | ||

108 | Cows and Primitive Roots | Codeforces | Codeforces Round #174 (Div. 2) | 3 | |

109 | DDF | UVA | 3 | ||

110 | A Trivial Problem | Codeforces | Manthan, Codefest 16 | 3 | |

111 | Primes or Palindromes? | Codeforces | Codeforces Round #315 (Div. 1) & Codeforces Round #315 (Div. 2) | 3 | |

112 | Bear and Prime Numbers | Codeforces | Codeforces Round #226 (Div. 2) | 3 | |

113 | Fox Dividing Cheese | Codeforces | Codeforces Round #218 (Div. 2) | 3 | |

114 | Levko and Permutation | Codeforces | Codeforces Round #210 (Div. 2) | 3 | |

115 | Quiz | Codeforces | Codeforces Round #196 (Div. 2) & Codeforces Round #196 (Div. 1) | 3 | |

116 | Routine Problem | Codeforces | Codeforces Round #196 (Div. 2) | 3 | |

117 | Good Sequences | Codeforces | Codeforces Round #162 (Div. 1) & Codeforces Round #162 (Div. 2) | 3 | |

118 | Permutation Primes | Live Archive | 2004 | Asia - Dhaka | 3 |

119 | Primal Fear | SPOJ | 3 | ||

120 | The Meaningless Game | Codeforces | Codeforces Round #426 (Div. 1) & Codeforces Round #426 (Div. 2) | 3 | |

121 | Mike and gcd problem | Codeforces | Codeforces Round #410 (Div. 2) | 3 | |

122 | Eugeny and Play List | Codeforces | Codeforces Round #182 (Div. 2) | 3 | |

123 | The Super Powers | UVA | 3 | ||

124 | SETI | SPOJ | 4 | ||

125 | Rank of a Fraction | SPOJ | 4 | ||

126 | N DIV PHI_N (Hard) | SPOJ | 4 | ||

127 | Chilly Willy | Codeforces | Codeforces Round #152 (Div. 2) | 4 | |

128 | Well-known Numbers | Codeforces | Codeforces Round #139 (Div. 2) | 4 | |

129 | Colliders | Codeforces | Codeforces Round #109 (Div. 1) & Codeforces Round #109 (Div. 2) | 4 | |

130 | Petya and Divisors | Codeforces | Codeforces Beta Round #85 (Div. 1 Only) & Codeforces Beta Round #85 (Div. 2 Only) | 4 | |

131 | Round Table Knights | Codeforces | Codeforces Beta Round #65 (Div. 2) | 4 | |

132 | Irrational problem | Codeforces | Codeforces Beta Round #62 | 4 | |

133 | Fortune Telling | Codeforces | Codeforces Beta Round #55 (Div. 2) | 4 | |

134 | Dots | SPOJ | 4 | ||

135 | Skyscraper Floors | UVA | 4 | ||

136 | Boring Card Game | Live Archive | 2011 | Europe - Central | 4 |

137 | Gaussian Prime Factors | Live Archive | 2006 | Asia - Manila | 4 |

138 | Broken Keyboard | UVA | 4 | ||

139 | Subtraction | A2 Online Judge | 4 | ||

140 | Multipliers | Codeforces | Codeforces Round #338 (Div. 2) | 4 | |

141 | Gerald and Giant Chess | Codeforces | Codeforces Round #313 (Div. 1) & Codeforces Round #313 (Div. 2) | 4 | |

142 | Ant colony | Codeforces | Codeforces Round #271 (Div. 2) | 4 | |

143 | Devu and Partitioning of the Array | Codeforces | Codeforces Round #251 (Div. 2) | 4 | |

144 | Divisible by Seven | Codeforces | Codeforces Round #221 (Div. 1) & Codeforces Round #221 (Div. 2) | 4 | |

145 | Find Maximum | Codeforces | Codeforces Round #205 (Div. 2) | 4 | |

146 | Ksusha and Array | Codeforces | Croc Champ 2013 - Round 2 (Div. 2 Edition) | 4 | |

147 | Subtractions | Codeforces | Codeforces Testing Round #5 | 4 | |

148 | Fox And Jumping | Codeforces | Codeforces Round #290 (Div. 2) & Codeforces Round #290 (Div. 1) | 4 | |

149 | Remainders Game | Codeforces | Codeforces Round #360 (Div. 1) & Codeforces Round #360 (Div. 2) | 4 | |

150 | Ralph And His Magic Field | Codeforces | Codeforces Round #447 (Div. 2) | 4 | |

151 | The Most Complex Number | Timus | 4 | ||

152 | Rectangular Game | Codeforces | ABBYY Cup 2.0 - Easy | 5 | |

153 | Rectangular Game | Codeforces | ABBYY Cup 2.0 - Easy | 5 | |

154 | Pseudorandom Sequence Period | Codeforces | Croc Champ 2012 - Qualification Round | 5 | |

155 | Prime Permutation | Codeforces | Codeforces Beta Round #92 (Div. 1 Only) & Codeforces Beta Round #92 (Div. 2 Only) | 5 | |

156 | Petya and His Friends | Codeforces | Codeforces Beta Round #61 (Div. 2) | 5 | |

157 | Number With The Given Amount Of Divisors | Codeforces | Codeforces Beta Round #27 (Codeforces format, Div. 2) | 5 | |

158 | Monitor | Codeforces | Codeforces Beta Round #16 (Div. 2 Only) | 5 | |

159 | Line | Codeforces | Codeforces Beta Round #7 | 5 | |

160 | Moodular Arithmetic | Codeforces | Codeforces Round #334 (Div. 1) & Codeforces Round #334 (Div. 2) | 5 | |

161 | Clique in the Divisibility Graph | Codeforces | VK Cup 2015 - Finals, online mirror | 5 | |

162 | Mike and Foam | Codeforces | Codeforces Round #305 (Div. 1) & Codeforces Round #305 (Div. 2) | 5 | |

163 | Array and Operations | Codeforces | Codeforces Round #284 (Div. 1) & Codeforces Round #284 (Div. 2) | 5 | |

164 | Chocolate | Codeforces | Codeforces Round #279 (Div. 2) | 5 | |

165 | Roman and Numbers | Codeforces | Codeforces Round #235 (Div. 2) | 5 | |

166 | Vasya and Beautiful Arrays | Codeforces | Codeforces Round #206 (Div. 1) & Codeforces Round #206 (Div. 2) | 5 | |

167 | Vasily the Bear and Sequence | Codeforces | Codeforces Round #195 (Div. 2) | 5 | |

168 | Shaass and Lights | Codeforces | Codeforces Round #178 (Div. 2) | 5 | |

169 | Upgrading Array | Codeforces | Codeforces Round #236 (Div. 2) & Codeforces Round #236 (Div. 1) | 5 | |

170 | Tutorial BFS | SPOJ | 5 | ||

171 | Winter is here | Codeforces | Codeforces Round #428 (Div. 2) | 5 | |

172 | Anton and School - 2 | Codeforces | Codeforces Round #404 (Div. 2) | 5 | |

173 | Palindrome Degree | Codeforces | Codeforces Beta Round #7 | 5 | |

174 | Polygon Encoder | SPOJ | 6 | ||

175 | Printing some primes (Hard) | SPOJ | 6 | ||

176 | Reducing Fractions | Codeforces | Codeforces Round #137 (Div. 2) | 6 | |

177 | Calendar Reform | Codeforces | Croc Champ 2012 - Qualification Round | 6 | |

178 | Very Interesting Game | Codeforces | Codeforces Beta Round #88 | 6 | |

179 | Beaver Game | Codeforces | Codeforces Beta Round #70 (Div. 2) | 6 | |

180 | Longest Subsequence | Codeforces | Educational Codeforces Round 9 | 6 | |

181 | Array GCD | Codeforces | AIM Tech Round (Div. 1) & AIM Tech Round (Div. 2) | 6 | |

182 | Bots | Codeforces | Bubble Cup 8 - Finals [Online Mirror] | 6 | |

183 | GukiZ and Binary Operations | Codeforces | Codeforces Round #307 (Div. 2) | 6 | |

184 | Pluses everywhere | Codeforces | Codeforces Round #295 (Div. 2) & Codeforces Round #295 (Div. 1) | 6 | |

185 | Prefix Product Sequence | Codeforces | Codeforces Round #278 (Div. 1) & Codeforces Round #278 (Div. 2) | 6 | |

186 | Devu and Flowers | Codeforces | Codeforces Round #258 (Div. 2) | 6 | |

187 | Jzzhu and Apples | Codeforces | Codeforces Round #257 (Div. 1) & Codeforces Round #257 (Div. 2) | 6 | |

188 | Divisors | Codeforces | Codeforces Round #256 (Div. 2) | 6 | |

189 | DZY Loves Fibonacci Numbers | Codeforces | Codeforces Round #255 (Div. 1) & Codeforces Round #255 (Div. 2) | 6 | |

190 | Apple Tree | Codeforces | Codeforces Round #202 (Div. 1) & Codeforces Round #202 (Div. 2) | 6 | |

191 | Lucky Permutation | Codeforces | Codeforces Beta Round #91 (Div. 1 Only) & Codeforces Beta Round #91 (Div. 2 Only) | 6 | |

192 | Beautiful numbers | Codeforces | Codeforces Beta Round #51 | 6 | |

193 | Goldbach++ | Live Archive | 2005 | North America - Southeast USA | 6 |

194 | Unusual Sequences | Codeforces | Codeforces Round #450 (Div. 2) | 6 | |

195 | ZS and The Birthday Paradox | Codeforces | Codeforces Round #369 (Div. 2) | 6 | |

196 | Integer Factorization (29 digits) | SPOJ | 7 | ||

197 | Finding the Kth Prime (Hard) | SPOJ | 7 | ||

198 | Number Transformation | Codeforces | Codeforces Round #153 (Div. 1) & Codeforces Round #153 (Div. 2) | 7 | |

199 | Pairs of Numbers | Codeforces | Codeforces Testing Round #3 | 7 | |

200 | Double Happiness | Codeforces | Codeforces Beta Round #86 (Div. 1 Only) & Codeforces Beta Round #86 (Div. 2 Only) | 7 | |

201 | Chessboard Billiard | Codeforces | Codeforces Beta Round #68 | 7 | |

202 | Digital Root | Codeforces | Codeforces Beta Round #10 | 7 | |

203 | Sum of Remainders | Codeforces | Educational Codeforces Round 5 | 7 | |

204 | Alice, Bob, Oranges and Apples | Codeforces | Codeforces Round #325 (Div. 1) & Codeforces Round #325 (Div. 2) | 7 | |

205 | Traffic Jams in the Land | Codeforces | Codeforces Round #284 (Div. 1) | 7 | |

206 | On Sum of Fractions | Codeforces | Codeforces Round #232 (Div. 1) & Codeforces Round #232 (Div. 2) | 7 | |

207 | On Number of Decompositions into Multipliers | Codeforces | Codeforces Round #232 (Div. 1) & Codeforces Round #232 (Div. 2) | 7 | |

208 | Divisor Tree | Codeforces | Codeforces Round #196 (Div. 2) & Codeforces Round #196 (Div. 1) | 7 | |

209 | ucyhf | Codeforces | April Fools Day Contest | 7 | |

210 | Bamboo Partition | Codeforces | Codeforces Round #424 (Div. 1, rated, based on VK Cup Finals) & Codeforces Round #424 (Div. 2, rated, based on VK Cup Finals) | 7 | |

211 | Fractions | UVA | 8 | ||

212 | Number Challenge | Codeforces | Codeforces Round #146 (Div. 1) | 8 | |

213 | Anniversary | Codeforces | Codeforces Round #140 (Div. 1) & Codeforces Round #140 (Div. 2) | 8 | |

214 | Unsolvable | Codeforces | Codeforces Round #139 (Div. 2) | 8 | |

215 | Martian Luck | Codeforces | Codeforces Round #133 (Div. 2) | 8 | |

216 | Periodical Numbers | Codeforces | Codeforces Round #132 (Div. 2) | 8 | |

217 | Numbers | Codeforces | Codeforces Beta Round #72 (Div. 1 Only) | 8 | |

218 | Prime Problem | Codeforces | School Team Contest #3 (Winter Computer School 2010/11) | 8 | |

219 | Notepad | Codeforces | Codeforces Beta Round #17 | 8 | |

220 | Cowslip Collections | Codeforces | CROC 2016 - Elimination Round | 8 | |

221 | REQ | Codeforces | Codeforces Round #330 (Div. 1) | 8 | |

222 | Superior Periodic Subarrays | Codeforces | Codeforces Round #323 (Div. 1) & Codeforces Round #323 (Div. 2) | 8 | |

223 | The Child and Binary Tree | Codeforces | Codeforces Round #250 (Div. 1) | 8 | |

224 | Beautiful Set | Codeforces | Codeforces Round #213 (Div. 1) & Codeforces Round #213 (Div. 2) | 8 | |

225 | GCD Table | Codeforces | Codeforces Round #196 (Div. 1) | 8 | |

226 | Cube Problem | Codeforces | Croc Champ 2013 - Round 2 | 8 | |

227 | Cows and Cool Sequences | Codeforces | Codeforces Round #174 (Div. 1) | 8 | |

228 | Three Horses | Codeforces | Codeforces Round #166 (Div. 2) | 8 | |

229 | Ultimate Weirdness of an Array | Codeforces | Codeforces Round #352 (Div. 1) & Codeforces Round #352 (Div. 2) | 8 | |

230 | Timofey and remoduling | Codeforces | Codeforces Round #395 (Div. 1) & Codeforces Round #395 (Div. 2) | 8 | |

231 | Mishka and Divisors | Codeforces | Codeforces Round #365 (Div. 2) | 8 | |

232 | Ada and Connections | SPOJ | 8 | ||

233 | Tractor College | Codeforces | Codeforces Round #126 (Div. 2) | 9 | |

234 | Visit of the Great | Codeforces | Codeforces Round #118 (Div. 1) | 9 | |

235 | Divisibility Rules | Codeforces | Codeforces Round #116 (Div. 2, ACM-ICPC Rules) | 9 | |

236 | Morrowindows | Codeforces | Codeforces Beta Round #66 | 9 | |

237 | Swap (Easy - Level 2) | SPOJ | 9 | ||

238 | Four Divisors | Codeforces | Educational Codeforces Round 12 | 9 | |

239 | Present for Vitalik the Philatelist | Codeforces | Codeforces Round #325 (Div. 1) | 9 | |

240 | Superhero's Job | Codeforces | VK Cup 2015 - Round 3 (unofficial online mirror, Div. 1 only) | 9 | |

241 | Levko and Sets | Codeforces | Codeforces Round #210 (Div. 1) | 9 | |

242 | White, Black and White Again | Codeforces | Testing Round #6 | 9 | |

243 | Rotatable Number | Codeforces | Codeforces Round #183 (Div. 1) | 9 | |

244 | Shaass and Painter Robot | Codeforces | Codeforces Round #178 (Div. 2) | 9 | |

245 | Prime factorization | Codeforces | VK Cup 2012 Wild-card Round 1 | 10 | |

246 | Number of Binominal Coefficients | Codeforces | Codeforces Round #323 (Div. 1) | 10 | |

247 | New Year Running | Codeforces | Good Bye 2014 | 10 | |

248 | Jzzhu and Squares | Codeforces | Codeforces Round #257 (Div. 1) | 10 | |

249 | Mister B and Beacons on Field | Codeforces | Codeforces Round #421 (Div. 1) & Codeforces Round #421 (Div. 2) | 10 | |

250 | Mister B and Astronomers | Codeforces | Codeforces Round #421 (Div. 1) | 10 | |

251 | Nephren Runs a Cinema | Codeforces | Codeforces Round #449 (Div. 1) | 10 |