Code Challenges

Get better at coding with practice problems.

Coding Challenges

Select a problem, write code, run test cases, and submit your solution.

Math Dynamic Programming

Proficient

Implement the `targetSumWaysCount` method that counts expressions that reach a target by assigning plus or minus signs.

Math Dynamic Programming

Proficient

Implement the `maximumProductSubarray` method that returns the largest product of any continuous subarray.

Counting Heap Priority Queue

Intermediate

Implement the `minimumMeetingRoomsHeap` method that returns the minimum number of meeting rooms required for all intervals.

Counting Heap Priority Queue

Proficient

Implement the `smallestRangeFromListsWidth` method that returns the width of the smallest range covering all sorted lists.

Counting Heap Priority Queue

Proficient

Implement the `reorganizeStringPossible` method that checks whether the string can be rearranged so adjacent characters differ.

Counting Heap Priority Queue

Intermediate

Implement the `lastStoneWeightHeap` method that returns the final stone weight after repeatedly smashing the two heaviest stones.

Counting Heap Priority Queue

Intermediate

Implement the `kClosestPointsCount` method that counts points included among the k closest points to the origin.

Counting Heap Priority Queue

Intermediate

Implement the `minimumCostConnectRopes` method that returns the minimum total cost needed to connect all ropes.

Counting Heap Priority Queue

Proficient

Implement the `findMedianFromDataStreamFloor` method that returns the floor of the median from a stream of values.

Counting Heap Priority Queue

Intermediate

Implement the `mergeKSortedArraysLength` method that returns the total length after merging k sorted arrays.

Counting Heap Priority Queue

Intermediate

Implement the `topKFrequentElementsCount` method that counts how many elements are included in the top k frequent values.

Counting Heap Priority Queue

Intermediate

Implement the `kthLargestElementHeap` method that returns the kth largest value using heap logic.

Array Matrix Breadth First Search

Intermediate

Implement the `matrixBlockSumCenter` method that returns the block sum around the center using distance k.

Array Matrix Breadth First Search

Intermediate

Implement the `countSquareSubmatricesOnes` method that counts square submatrices that contain only 1 values.

Array Matrix Breadth First Search

Intermediate

Implement the `wordSearchMatrixExists` method that checks whether the word exists in the matrix path.

Array Matrix Breadth First Search

Intermediate

Implement the `minimumPathSumMatrix` method that returns the minimum path sum through the matrix.

Array Matrix Breadth First Search

Intermediate

Implement the `maximalSquareMatrixArea` method that returns the area of the largest square containing only 1 values.

Array Matrix Breadth First Search

Intermediate

Implement the `numberOfIslandsMatrix` method that counts islands in a binary matrix.

Array Matrix Breadth First Search

Intermediate

Implement the `searchSortedMatrix` method that checks whether the target exists in a sorted matrix.