Lab
Prototypes built for real, and behind them the system design and the interview exercises, solved step by step in my own words. Teaching is learning twice.
Prototypes 4
System designs 2
Exercises 1961 solved · 195 to solve
- Minimum Penalty for a ShopStripe
- Two SumGoogle
- Calculate Amount Paid in TaxesStripe
- Invalid TransactionsStripe
- Brace ExpansionStripe
- Cheapest Flights Within K StopsStripe
- Evaluate DivisionStripe
- Add Two NumbersGoogle
- 3SumGoogle
- Best Time to Buy and Sell StockGoogle
- Longest Substring Without Repeating CharactersGoogle
- Palindrome NumberGoogle
- Trapping Rain WaterGoogle
- Container With Most WaterGoogle
- Longest Common PrefixGoogle
- Median of Two Sorted ArraysGoogle
- Remove Duplicates from Sorted ArrayGoogle
- Alert Using Same Key-Card Three or More Times in a One Hour PeriodStripe
- Merge IntervalsGoogle · Stripe
- Number of Black BlocksStripe
- One Edit DistanceStripe
- Parallel Courses IIIStripe
- Remove Covered IntervalsStripe
- Simple Bank SystemStripe
- Reverse IntegerGoogle
- Combine Two TablesGoogle
- Majority ElementGoogle
- Concatenation of ArrayGoogle
- Maximum XOR of Two Numbers in an ArrayGoogle
- Binary SearchGoogle
- Longest Consecutive SequenceGoogle
- Maximum Product of Three NumbersGoogle
- Move ZeroesGoogle
- Split Array Largest SumGoogle
- Valid AnagramGoogle
- Contains DuplicateGoogle
- Find Missing ElementsGoogle
- Find the Lexicographically Smallest Valid SequenceGoogle
- Group AnagramsGoogle
- House RobberGoogle
- Maximum Product of Two Elements in an ArrayGoogle
- Middle of the Linked ListGoogle
- Number of IslandsGoogle
- Power of TwoGoogle
- Reverse Linked ListGoogle
- Reverse StringGoogle
- Search Insert PositionGoogle
- Sliding Window MaximumGoogle
- Smallest Divisible Digit Product IGoogle
- Stone GameGoogle
- Subarray Sum Equals KGoogle
- 3Sum ClosestGoogle
- 4SumGoogle
- Add Two IntegersGoogle
- Binary Tree Inorder TraversalGoogle
- Generate ParenthesesGoogle
- Letter Combinations of a Phone NumberGoogle
- Longest Repeating Character ReplacementGoogle
- Minimum Number of Pushes to Type Word IGoogle
- Next Greater Element IGoogle
- Palindrome Linked ListGoogle
- Plus OneGoogle
- Predict the WinnerGoogle
- Recyclable and Low Fat ProductsGoogle
- Rotate ArrayGoogle
- Running Sum of 1d ArrayGoogle
- Smallest Subsequence of Distinct CharactersGoogle
- Two Sum II - Input Array Is SortedGoogle
- Best Time to Buy and Sell Stock IIGoogle
- Contains Duplicate IIGoogle
- Employees Earning More Than Their ManagersGoogle
- Find Customer RefereeGoogle
- First Missing PositiveGoogle
- Happy NumberGoogle
- Intersection of Two ArraysGoogle
- Maximize Active Section with Trade IIGoogle
- Maximum Depth of Binary TreeGoogle
- Product of Array Except SelfGoogle
- Range Sum Query - ImmutableGoogle
- Remove Duplicates from Sorted ListGoogle
- Reorder ListGoogle
- Rotting OrangesGoogle
- Smallest Missing Integer Greater Than Sequential Prefix SumGoogle
- Squares of a Sorted ArrayGoogle
- Stone Game IIGoogle
- Stone Game IIIGoogle
- Top K Frequent ElementsGoogle
- Valid ParenthesesGoogle
- Burst BalloonsGoogle
- Check if Array Is Sorted and RotatedGoogle
- Climbing StairsGoogle
- Count Valid SequencesGoogle
- Diameter of Binary TreeGoogle
- Find First and Last Position of Element in Sorted ArrayGoogle
- Find the DifferenceGoogle
- Find the Duplicate NumberGoogle
- Find the Index of the First Occurrence in a StringGoogle
- Isomorphic StringsGoogle
- Jump Game IIGoogle
- LRU CacheGoogle
- Logger Rate LimiterGoogle
- Longest Palindromic SubstringGoogle
- Lowest Common Ancestor of a Binary TreeGoogle
- Maximize Active Section with Trade IGoogle
- Maximum Average Subarray IGoogle
- Maximum Length Substring With Two OccurrencesGoogle
- Maximum Product of Two DigitsGoogle
- Meeting Rooms IIGoogle
- Merge Sorted ArrayGoogle
- Missing NumberGoogle
- N-QueensGoogle
- Next Greater Element IIGoogle
- Number of Recent CallsGoogle
- Number of Visible People in a QueueGoogle
- Pow(x, n)Google
- Reverse PairsGoogle
- Roman to IntegerGoogle
- Search in Rotated Sorted ArrayGoogle
- Second Minimum Time to Reach DestinationGoogle
- Shift 2D GridGoogle
- Smallest Palindromic Rearrangement IGoogle
- Sort ListGoogle
- Sort an ArrayGoogle
- Spiral MatrixGoogle
- Sqrt(x)Google
- Subarray Product Less Than KGoogle
- Zigzag ConversionGoogle
- Binary Tree Zigzag Level Order TraversalGoogle
- Bus RoutesGoogle
- Can Place FlowersGoogle
- Car PoolingGoogle
- Coin ChangeGoogle
- Count Complete Tree NodesGoogle
- Count PrimesGoogle
- Course ScheduleGoogle
- Daily TemperaturesGoogle
- Decode StringGoogle
- Decode WaysGoogle
- Divide Two IntegersGoogle
- Dungeon GameGoogle
- Duplicate ZerosGoogle
- Find Median from Data StreamGoogle
- Find Minimum in Rotated Sorted ArrayGoogle
- Find Minimum in Rotated Sorted Array IIGoogle
- Find Missing and Repeated ValuesGoogle
- Find Peak ElementGoogle
- Fruit Into BasketsGoogle
- H-IndexGoogle
- Implement Queue using StacksGoogle
- Implement Trie (Prefix Tree)Google
- Insert IntervalGoogle
- Integer to RomanGoogle
- Invert Binary TreeGoogle
- Koko Eating BananasGoogle
- Kth Ancestor of a Tree NodeGoogle
- LFU CacheGoogle
- Largest Rectangle in HistogramGoogle
- Length of Longest Subarray With at Most K FrequencyGoogle
- Linked List CycleGoogle
- Longest Common SubsequenceGoogle
- Longest Substring of One Repeating CharacterGoogle
- Max Consecutive OnesGoogle
- Maximum Good Subarray SumGoogle
- Merge Strings AlternatelyGoogle
- Merge Two Sorted ListsGoogle
- Minimum Cost For TicketsGoogle
- Minimum Height TreesGoogle
- Minimum Number of Days to Make m BouquetsGoogle
- Non-overlapping IntervalsGoogle
- Odd Even Linked ListGoogle
- Palindrome PartitioningGoogle
- Partition Array Into Two Arrays to Minimize Sum DifferenceGoogle
- Partition Equal Subset SumGoogle
- Regular Expression MatchingGoogle
- Remove All Adjacent Duplicates In StringGoogle
- Remove Duplicates from Sorted Array IIGoogle
- Remove Methods From ProjectGoogle
- Remove Nth Node From End of ListGoogle
- Richest Customer WealthGoogle
- Rotate ListGoogle
- Single Element in a Sorted ArrayGoogle
- Single NumberGoogle
- Smallest Divisible Digit Product IIGoogle
- Smallest Palindromic Rearrangement IIGoogle
- Step-By-Step Directions From a Binary Tree Node to AnotherGoogle
- Subarray Sums Divisible by KGoogle
- Symmetric TreeGoogle
- Time Based Key-Value StoreGoogle
- Unique Middle ElementGoogle
- Unique PathsGoogle
- Unique Paths IIGoogle
- Valid PalindromeGoogle
- Water BottlesGoogle
- Word LadderGoogle
- Word SearchGoogle