Code Challenges

Get better at coding with practice problems.

Coding Challenges

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

Array String Hash Map Sliding Window

Guru

Implement the `shortestSubarrayAtLeastKLength` method that returns the shortest subarray length with sum at least k.

Array String Hash Map Sliding Window

Intermediate

Implement the `boundedMaximumSubarrayCount` method that counts subarrays whose maximum value stays within a given range.

Array String Hash Map Sliding Window

Intermediate

Implement the `longestSubstringAtMostKDistinctLength` method that returns the longest substring length with at most k distinct characters.

Array String Hash Map Sliding Window

Intermediate

Implement the `countNiceSubarrays` method that counts subarrays that contain exactly k odd numbers.

Array String Hash Map Sliding Window

Intermediate

Implement the `longestSubarrayAfterDeletingOne` method that returns the longest subarray of 1 values after deleting one element.

Array String Hash Map Sliding Window

Intermediate

Implement the `fruitIntoBasketsMaxCount` method that returns the maximum fruits collected using at most two fruit types.

Array String Hash Map Sliding Window

Intermediate

Implement the `maxConsecutiveOnesWithKFlips` method that returns the longest run of 1 values after flipping at most k zeroes.

Array String Hash Map Sliding Window

Proficient

Implement the `longestRepeatingCharReplacement` method that returns the longest substring length after replacing at most k characters.

Array String Hash Map Sliding Window

Intermediate

Implement the `findAnagramStartCount` method that counts starting positions where an anagram of the pattern appears.

Array String Hash Map Sliding Window

Intermediate

Implement the `permutationInStringCheck` method that checks whether the text contains any permutation of the pattern.

Array String Hash Map Sliding Window

Learner

Implement the `maximumAverageSubarrayFloor` method that returns the floor of the maximum average of a fixed-length subarray.

Array String Hash Map Sliding Window

Intermediate

Implement the `minimumSizeSubarraySum` method that returns the smallest subarray length whose sum reaches the target.

Array String Hash Map Sliding Window

Intermediate

Implement the `longestSubstringWithKDistinct` method that returns the longest substring length with at most k distinct characters.

String Manipulation String Counting Sliding Window

Intermediate

Implement the `longestSubstringWithoutRepeat` method that returns the length of the longest substring that has no repeated characters.

Array Prefix Sum Sliding Window

Intermediate

Implement the `maximumSubarraySumFixedLength` method that finds the maximum sum of any contiguous subarray of length k.

String Hash Map Sliding Window

Guru

Implement the method `minimumWindowLength` that returns the length of the smallest substring containing all required characters.

String Hash Map Sliding Window

Proficient

Implement the method `longestUniqueSubstring` that returns the length of the longest substring without repeated characters.