Practice Problems

Problem of the Day: Integer Square Root — keep your streak alive!

Practice Problems — implementation

#ProblemTopicsDifficulty
46 Balanced Brackets implementation strings 1000
113 Evens First, Order Kept implementation sorting 1000
123 Rotate Right by K implementation 1000
132 Symmetric Matrix implementation 1000
175 Armstrong Number math implementation 1000
273 Exactly One Side implementation 1000
284 Collatz Steps math implementation 1000
285 Collatz Peak math implementation 1000
315 Valid Integer implementation strings 1000
317 Strong Enough Password implementation strings 1000
318 Valid Username implementation strings 1000
325 Sum of the Others implementation 1000
338 Equal Pairs implementation 1000
349 12-Hour to 24-Hour implementation 1000
354 The Careful Bank implementation 1000
355 First Stockout Day implementation 1000
357 Election Night implementation 1000
361 Dry Spells implementation 1000
377 Diamond implementation 1000
378 The Letter X implementation 1000
385 Closest to 21 implementation 1000
425 Additive Sequence math implementation 1000
428 A True Permutation implementation 1000
469 How Many Times Does X Appear implementation 1000
488 Boustrophedon implementation 1000
492 Twice as Large implementation 1000
16 Count Sign Changes implementation 1100
20 Majority Element implementation 1100
48 Candy Rounds implementation 1100
119 Third Distinct Maximum implementation 1100
129 Alternating Parity Stretch implementation 1100
178 Multiplicative Persistence math implementation 1100
271 Common Elements implementation 1100
347 Spreadsheet Column Number math implementation 1100
439 Digit Duel implementation 1100
489 Anti-Diagonal Sums implementation 1100
490 Toeplitz Matrix implementation 1100
31 Roman Numerals implementation 1200
134 Rotate 90 Degrees implementation 1200
176 Happy Number math implementation 1200
286 Look and Say implementation strings 1200
319 Valid IPv4 Address implementation strings 1200
346 Spreadsheet Column Name math implementation 1200
360 League Champion implementation 1200
383 Bulls and Cows implementation 1200
440 Forgetful Addition implementation 1200
470 Position of the K-th One implementation binary-search 1200
482 Longest Arithmetic Stretch implementation 1200
491 Magic Square implementation 1200
493 Parse the Number implementation strings 1200