Skip to content

For employers Sign in

Make and follow sheets.Sign in

Problems

691 problems

Has video Premium only Reset

Array2,237 String877 Hash Table797 Math691 Dynamic Programming673 Sorting508 Greedy485 Binary Search357 Depth-First Search338 Database308 Bit Manipulation286 Matrix279 Tree264 Breadth-First Search257 Prefix Sum252 All topics

691 results

Sign in to see which of these you have solved.Sign in

TitleSolutionAcceptDifficultyTopics

2. Add Two NumbersVideo

Solution49.3%Medium

Linked List, Math +1· 37 companies

7. Reverse IntegerVideo

Solution32.2%Medium

Math· 22 companies

9. Palindrome NumberVideo

Solution61.0%Easy

Math· 31 companies

12. Integer to RomanVideo

Solution71.8%Medium

Hash Table, Math +1· 31 companies

13. Roman to IntegerVideo

Solution67.0%Easy

Hash Table, Math +1· 36 companies

29. Divide Two IntegersVideo

Solution20.1%Medium

Bit Manipulation, Math· 8 companies

43. Multiply StringsVideo

Solution44.4%Medium

Math, Simulation +1· 17 companies

48. Rotate ImageVideo

Solution80.7%Medium

Array, Math +1· 36 companies

50. Pow(x, n)Video

Solution39.0%Medium

Math, Recursion· 22 companies

60. Permutation SequenceVideo

Solution54.3%Hard

Math, Recursion· 7 companies

62. Unique PathsVideo

Solution67.3%Medium

Combinatorics, Dynamic Programming +1· 21 companies

66. Plus OneVideo

Solution50.3%Easy

Array, Math· 13 companies

67. Add BinaryVideo

Solution58.4%Easy

Bit Manipulation, Math +2· 17 companies

69. Sqrt(x)Video

Solution42.2%Easy

Binary Search, Math· 17 companies

70. Climbing StairsVideo

Solution54.0%Easy

Dynamic Programming, Math +1· 37 companies

89. Gray CodeVideo

Solution66.2%Medium

Backtracking, Bit Manipulation +1· 5 companies

96. Unique Binary Search TreesVideo

Solution64.0%Medium

Binary Search Tree, Binary Tree +3· 10 companies

149. Max Points on a LineVideo

Solution31.6%Hard

Array, Geometry +2· 16 companies

150. Evaluate Reverse Polish NotationVideo

Solution58.5%Medium

Array, Math +1· 18 companies

166. Fraction to Recurring DecimalVideo

Solution31.3%Medium

Hash Table, Math +1· 10 companies

168. Excel Sheet Column TitleVideo

Solution47.9%Easy

Math, String· 10 companies

171. Excel Sheet Column NumberVideo

Solution68.6%Easy

Math, String· 9 companies

172. Factorial Trailing ZeroesVideo

Solution47.5%Medium

Math· 5 companies

189. Rotate ArrayVideo

Solution45.3%Medium

Array, Math +1· 27 companies

202. Happy NumberVideo

Solution60.0%Easy

Hash Table, Math +1· 27 companies

204. Count PrimesVideo

Solution35.8%Medium

Array, Enumeration +2· 17 companies

223. Rectangle AreaVideo

Solution50.3%Medium

Geometry, Math· 7 companies

224. Basic CalculatorVideo

Solution47.3%Hard

Math, Recursion +2· 25 companies

227. Basic Calculator IIVideo

Solution47.3%Medium

Math, Stack +1· 32 companies

231. Power of TwoVideo

Solution50.5%Easy

Bit Manipulation, Math +1· 11 companies

233. Number of Digit OneVideo

Solution39.9%Hard

Dynamic Programming, Math +1· 6 companies

241. Different Ways to Add ParenthesesVideo

Solution73.7%Medium

Dynamic Programming, Math +3· 6 companies

258. Add DigitsVideo

Solution69.3%Easy

Math, Number Theory +1· 10 companies

263. Ugly NumberVideo

Solution43.9%Easy

Math· 8 companies

264. Ugly Number IIVideo

Solution49.7%Medium

Dynamic Programming, Hash Table +2· 9 companies

268. Missing NumberVideo

Solution72.4%Easy

Array, Binary Search +4· 19 companies

273. Integer to English WordsVideo

Solution34.9%Hard

Math, Recursion +1· 24 companies

279. Perfect SquaresVideo

Solution57.0%Medium

Breadth-First Search, Dynamic Programming +1· 12 companies

282. Expression Add OperatorsVideo

Solution43.5%Hard

Backtracking, Math +1· 7 companies

292. Nim GameVideo

Solution60.6%Easy

Brainteaser, Game Theory +1· 6 companies

294. Flip Game IIVideoPremium

Solution52.2%Medium

Backtracking, Dynamic Programming +3· 2 companies

296. Best Meeting PointVideoPremium

Solution61.1%Hard

Array, Math +2· 9 companies

313. Super Ugly NumberVideo

Solution46.6%Medium

Array, Dynamic Programming +1· 5 companies

319. Bulb SwitcherVideo

Solution56.2%Medium

Brainteaser, Math· 9 companies

326. Power of ThreeVideo

Solution51.4%Easy

Math, Recursion· 6 companies

335. Self CrossingVideo

Solution36.9%Hard

Array, Geometry +1· 1 company

342. Power of FourVideo

Solution52.5%Easy

Bit Manipulation, Math +1· 8 companies

343. Integer BreakVideo

Solution62.6%Medium

Dynamic Programming, Math· 6 companies

356. Line ReflectionVideoPremium

Solution36.3%Medium

Array, Hash Table +1· 2 companies

357. Count Numbers with Unique DigitsVideo

Solution56.1%Medium

Backtracking, Dynamic Programming +1· 5 companies

Showing 1–50 of 691