Problems

3,898+ problems · 938 Easy · 2039 Medium · 921 Hard

Title	Solution	Practice	Difficulty	Companies	Topics
601. Human Traffic of Stadium	Solution	Solve	Hard	Amazon+5	Database
602. Friend Requests II: Who Has the Most Friends	Solution	Solve	Medium	Amazon+4	Database
603. Consecutive Available Seats	Solution	Solve	Easy	-	Database
604. Design Compressed String Iterator	Solution	Solve	Easy	Google	Array Design+2
605. Can Place Flowers	Solution	Solve	Easy	Airbnb+15	Array Greedy
606. Construct String from Binary Tree	Solution	Solve	Medium	Amazon+2	Binary Tree Depth-First Search+2
607. Sales Person	Solution	Solve	Easy	Amazon+2	Database
608. Tree Node	Solution	Solve	Medium	Bloomberg+3	Database
609. Find Duplicate File in System	Solution	Solve	Medium	Amazon+7	Array Hash Table+1
610. Triangle Judgement	Solution	Solve	Easy	Amazon+4	Database
611. Valid Triangle Number	Solution	Solve	Medium	Amazon+8	Array Binary Search+3
612. Shortest Distance in a Plane	Solution	Solve	Medium	Meta	Database
613. Shortest Distance in a Line	Solution	Solve	Easy	-	Database
614. Second Degree Follower	Solution	Solve	Medium	-	Database
615. Average Salary: Departments VS Company	Solution	Solve	Hard	-	Database
616. Add Bold Tag in String	Solution	Solve	Medium	Google+5	Array Hash Table+3
617. Merge Two Binary Trees	Solution	Solve	Easy	Amazon+7	Binary Tree Breadth-First Search+2
618. Students Report By Geography	Solution	Solve	Hard	-	Database
619. Biggest Single Number	Solution	Solve	Easy	Amazon+2	Database
620. Not Boring Movies	Solution	Solve	Easy	Amazon+4	Database
621. Task Scheduler	Solution	Solve	Medium	Adobe+29	Array Counting+4
622. Design Circular Queue	Solution	Solve	Medium	Airbnb+21	Array Design+2
623. Add One Row to Tree	Solution	Solve	Medium	Bloomberg+4	Binary Tree Breadth-First Search+2
624. Maximum Distance in Arrays	Solution	Solve	Medium	Amazon+4	Array Greedy
625. Minimum Factorization	Solution	Solve	Medium	Tencent	Greedy Math
626. Exchange Seats	Solution	Solve	Medium	Amazon+8	Database
627. Swap Salary	Solution	Solve	Easy	Amazon+3	Database
628. Maximum Product of Three Numbers	Solution	Solve	Easy	Accenture+16	Array Math+1
629. K Inverse Pairs Array	Solution	Solve	Hard	Google+3	Dynamic Programming
630. Course Schedule III	Solution	Solve	Hard	Amazon+2	Array Greedy+2
631. Design Excel Sum Formula	Solution	Solve	Hard	Airbnb+8	Array Design+3
632. Smallest Range Covering Elements from K Lists	Solution	Solve	Hard	Amazon+10	Array Greedy+4
633. Sum of Square Numbers	Solution	Solve	Medium	Amazon+7	Binary Search Math+1
634. Find the Derangement of An Array	Solution	Solve	Medium	Ixl	Dynamic Programming Math
635. Design Log Storage System	Solution	Solve	Medium	Amazon+4	Design Hash Table+2
636. Exclusive Time of Functions	Solution	Solve	Medium	Amazon+10	Array Stack
637. Average of Levels in Binary Tree	Solution	Solve	Easy	Amazon+3	Binary Tree Breadth-First Search+2
638. Shopping Offers	Solution	Solve	Medium	Adobe+5	Array Backtracking+4
639. Decode Ways II	Solution	Solve	Hard	Meta+1	Dynamic Programming String
640. Solve the Equation	Solution	Solve	Medium	Amazon+1	Math Simulation+1
641. Design Circular Deque	Solution	Solve	Medium	Amazon+3	Array Design+2
642. Design Search Autocomplete System	Solution	Solve	Hard	Amazon+13	Data Stream Depth-First Search+5
643. Maximum Average Subarray I	Solution	Solve	Easy	Amazon+9	Array Sliding Window
644. Maximum Average Subarray II	Solution	Solve	Hard	Google	Array Binary Search+1
645. Set Mismatch	Solution	Solve	Easy	Amazon+5	Array Bit Manipulation+2
646. Maximum Length of Pair Chain	Solution	Solve	Medium	Amazon+2	Array Dynamic Programming+2
647. Palindromic Substrings	Solution	Solve	Medium	Amazon+22	Dynamic Programming String+1
648. Replace Words	Solution	Solve	Medium	Amazon+5	Array Hash Table+2
649. Dota2 Senate	Solution	Solve	Medium	Amazon+5	Greedy Queue+1
650. 2 Keys Keyboard	Solution	Solve	Medium	Amazon+6	Dynamic Programming Math