Coding interview problems
3,736 problems: 937 Easy, 1,914 Medium, 885 Hard. Each runs against hidden tests, in 13 languages; database problems in SQL. Free for members.
Solve them in the app Explore guides
Problems 201–300 of 3,736
- 201. Shortest Clock Gap Medium · String, Sorting, Math
- 202. Next Time With the Same Digits Medium · String, Math
- 203. Upside-Down Numbers Medium · String, Recursion
- 204. Disjoint Word Product Medium · String, Bit Manipulation, Array
- 205. Longest Balanced-Case Substring Medium · String, Divide and Conquer, Hash Table
- 206. Substrings With At Most One Odd Letter Medium · String, Bit Manipulation, Hash Table, Prefix Sum
- 207. Peel Matching Ends Medium · String, Two Pointers
- 208. Grandest Merge Medium · String, Greedy, Two Pointers
- 209. One Step Back Letters Medium · String, Greedy
- 210. Smallest Word With a Weight Medium · String, Greedy
- 211. Spoil the Mirror Medium · String, Greedy
- 212. Rover With Obstacles Medium · Array, Hash Table, Simulation
- 213. Does the Rover Stay Close? Medium · String, Math, Simulation
- 214. Skyline-Safe Raise Medium · Array, Matrix, Greedy
- 215. Flip Columns for Uniform Rows Medium · Array, Matrix, Hash Table
- 216. Best Binary Row Score Medium · Array, Matrix, Greedy, Bit Manipulation
- 217. Grid From Its Margins Medium · Array, Matrix, Greedy
- 218. Servers That Can Talk Medium · Array, Matrix, Counting
- 219. Rows Equal to Columns Medium · Array, Matrix, Hash Table
- 220. First Full Line Painted Medium · Array, Matrix, Hash Table
- 221. Rotate the Grid Rings Medium · Array, Matrix, Simulation
- 222. Sorted Grid Lookup Medium · Array, Matrix, Binary Search, Divide and Conquer
- 223. Level the Grid Medium · Array, Matrix, Math, Sorting
- 224. Best Hourglass Medium · Array, Matrix, Prefix Sum
- 225. Rectangles With Ones at Corners Medium · Array, Matrix, Math, Dynamic Programming
- 226. Best Overlay of Two Images Medium · Array, Matrix
- 227. Tip the Box of Stones Medium · Array, Matrix, Two Pointers
- 228. Heavy-Left Cuts Medium · Array, Prefix Sum
- 229. Fairest Split Index Medium · Array, Prefix Sum
- 230. Distance Sums on a Sorted List Medium · Array, Math, Prefix Sum
- 231. Best Contiguous Total Medium · Array, Dynamic Programming, Divide and Conquer
- 232. Best Total on a Ring Medium · Array, Dynamic Programming, Queue
- 233. Best Contiguous Product Medium · Array, Dynamic Programming
- 234. Rotate or Sort the Queue Medium · String, Math, Sorting
- 235. Repeat Until It Fits Inside Medium · String
- 236. Compare by Smallest-Letter Frequency Medium · String, Array, Binary Search, Sorting
- 237. Count Triangle Triples Medium · Array, Two Pointers, Sorting, Binary Search
- 238. Equidistant Triples Medium · Array, Hash Table, Math
- 239. Two Plots Coverage Medium · Math
- 240. Four Corners Make a Square? Medium · Math
- 241. Smallest Axis Rectangle From Points Medium · Array, Hash Table, Math
- 242. Points per Circle Medium · Array, Math
- 243. Max Left Under Min Right Medium · Array, Prefix Sum
- 244. Bracket Balance Swaps Medium · String, Greedy, Two Pointers, Stack
- 245. Split the Nesting Depth Medium · String, Stack
- 246. Total Bit Disagreements Medium · Array, Bit Manipulation, Math
- 247. One-Bit Cycle Medium · Bit Manipulation, Math, Backtracking
- 248. Squads of Three Medium · Array, Dynamic Programming
- 249. Take From Both Ends Medium · Array, Sliding Window, Prefix Sum
- 250. Song Pairs That Fill Hours Medium · Array, Hash Table, Counting
- 251. Reverse-Twin Pairs Medium · Array, Hash Table, Math, Counting
- 252. Equal Product Quadruples Medium · Array, Hash Table, Counting
- 253. Fair Letter Split Medium · String, Hash Table, Dynamic Programming
- 254. Even-Vowel Stretch Medium · String, Hash Table, Bit Manipulation, Prefix Sum
- 255. Most Lamps on One Spot Medium · Array, Prefix Sum, Sorting
- 256. No Middle Averages Medium · Array, Greedy, Sorting
- 257. Tallest After Trimming Medium · Array, Greedy, Sorting
- 258. Mirror From Two-Letter Tiles Medium · String, Hash Table, Greedy, Counting
- 259. Best Turntable Score Medium · Array, Math, Dynamic Programming
- 260. Two Separate Windows Medium · Array, Sliding Window, Dynamic Programming
- 261. Near-Twin Words Medium · String, Hash Table
- 262. Drop Columns to Order the Rows Medium · String, Greedy, Array
- 263. Count Repeated Segments Medium · String, Hash Table, Sliding Window
- 264. Spiral Coordinates From a Start Cell Medium · Array, Matrix, Simulation
- 265. Group by Shift Pattern Medium · String, Hash Table
- 266. Rows of Words Within Width Easy · String, Greedy
- 267. Letter Runs on a Wheel Medium · String, Dynamic Programming
- 268. Double and Sweep Easy · Array, Simulation
- 269. Strided Sum Queries Medium · Array, Prefix Sum
- 270. Equal Vowel-Consonant Substrings Medium · String, Hash Table, Prefix Sum
- 271. Lucky Grid Lines Easy · Array, Matrix, Hash Table
- 272. Nearest Same Value Distance Easy · Array, Hash Table
- 273. Sum of Distances to Equals Medium · Array, Hash Table, Prefix Sum
- 274. Cumulative Letter Push Medium · String, Prefix Sum
- 275. Pairs With Equal Total Skill Medium · Array, Sorting, Two Pointers, Greedy
- 276. Find in a Row-Major Grid Medium · Array, Matrix, Binary Search
- 277. Sum of Floor Ratios Hard · Array, Math, Prefix Sum, Binary Search
- 278. Rubbish Rounds Medium · Array, String, Prefix Sum
- 279. Smaller to the Right Hard · Array, Binary Search, Divide and Conquer, Sorting
- 280. Shortest Mirror by Prepending Hard · String
- 281. Longest Border Hard · String
- 282. Longest Repeated Substring Hard · String, Binary Search, Hash Table
- 283. Count Distinct Substrings Hard · String, Trie, Hash Table
- 284. Two Odd Mirrors Hard · String
- 285. Best Rotation Score Hard · Array, Prefix Sum
- 286. Into a Checkerboard Hard · Array, Matrix, Bit Manipulation, Math
- 287. Sortable Blocks With Repeats Hard · Array, Stack, Greedy, Sorting, Monotonic Stack
- 288. Password Fixer Hard · String, Greedy
- 289. True or False Expression Hard · String, Stack, Recursion
- 290. Molecule Atom Count Hard · String, Stack, Hash Table, Sorting
- 291. Markup Validator Hard · String, Stack
- 292. Shortest Window Holding a Subsequence Hard · String, Dynamic Programming, Sliding Window
- 293. Total Subsequence Widths Hard · Array, Math, Sorting
- 294. Unique Letter Score Sum Hard · String, Dynamic Programming, Hash Table
- 295. Nearest Mirror Number Hard · String, Math
- 296. Smallest All-Ones Base Hard · Math, Binary Search
- 297. k-th in Dictionary Order Hard · Trie, Math
- 298. k-th Arrangement of 1..n Medium · Math, Recursion
- 299. Fewest Neighbour Swaps to a Mirror Hard · String, Greedy, Two Pointers
- 300. Swaps to the k-th Bigger Number Hard · String, Greedy, Two Pointers
