Solution for 301-400


# Name Difficulty Tags
301 Remove Invalid Parentheses Hard
303 Range Sum Query - Immutable Easy
304 Range Sum Query 2D - Immutable Medium
306 Additive Number Medium
307 Range Sum Query - Mutable Medium
309 Best Time to Buy and Sell Stock with Cooldown Medium
310 Minimum Height Trees Medium
312 Burst Balloons Hard
313 Super Ugly Number Medium
315 Count of Smaller Numbers After Self Hard
316 Remove Duplicate Letters Medium
318 Maximum Product of Word Lengths Medium
319 Bulb Switcher Medium
322 Coin Change Medium
323 Number of Connected Components in an Undirected Graph Medium
324 Wiggle Sort II Medium
326 Power of Three Easy
327 Count of Range Sum Hard
328 Odd Even Linked List Medium
329 Longest Increasing Path in a Matrix Hard
330 Patching Array Hard
331 Verify Preorder Serialization of a Binary Tree Medium
332 Reconstruct Itinerary Medium
333 Largest BST Subtree Medium Tree
334 Increasing Triplet Subsequence Medium
335 Self Crossing Hard
336 Palindrome Pairs Hard
337 House Robber III Medium Tree | Depth-first Search
338 Counting Bits Medium
341 Flatten Nested List Iterator Medium
342 Power of Four Easy
343 Integer Break Medium
344 Reverse String Easy
345 Reverse Vowels of a String Easy
347 Top K Frequent Elements Medium
349 Intersection of Two Arrays Easy
350 Intersection of Two Arrays II Easy
352 Data Stream as Disjoint Intervals Hard
354 Russian Doll Envelopes Hard
355 Design Twitter Medium
357 Count Numbers with Unique Digits Medium
365 Water and Jug Problem Medium
366 Find Leaves of Binary Tree Medium Tree | Depth-first Search
367 Valid Perfect Square Easy
368 Largest Divisible Subset Medium
371 Sum of Two Integers Medium
372 Super Pow Medium
373 Find K Pairs with Smallest Sums Medium
374 Guess Number Higher or Lower Easy
375 Guess Number Higher or Lower II Medium
376 Wiggle Subsequence Medium
377 Combination Sum IV Medium
378 Kth Smallest Element in a Sorted Matrix Medium
380 Insert Delete GetRandom O(1) Medium
381 Insert Delete GetRandom O(1) - Duplicates allowed Hard
382 Linked List Random Node Medium
383 Ransom Note Easy
384 Shuffle an Array Medium
385 Mini Parser Medium
386 Lexicographical Numbers Medium
387 First Unique Character in a String Easy
388 Longest Absolute File Path Medium
389 Find the Difference Easy
390 Elimination Game Medium
391 Perfect Rectangle Hard
392 Is Subsequence Easy
393 UTF-8 Validation Medium
394 Decode String Medium
395 Longest Substring with At Least K Repeating Characters Medium
396 Rotate Function Medium
397 Integer Replacement Medium
398 Random Pick Index Medium
399 Evaluate Division Medium
400 Nth Digit Medium