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 `stoneGameOptimalDifference` method that returns the best score difference when both players pick stones optimally.

Math Dynamic Programming

Guru

Implement the `minimumCostCutStick` method that returns the minimum total cost to cut a stick at given positions.

Math Dynamic Programming

Proficient

Implement the `distinctSubsequenceCount` method that counts how many subsequences of a source string equal a target string.

Math Dynamic Programming

Proficient

Implement the `interleavingStringCheck` method that checks whether one string is formed by interleaving two other strings.

Math Dynamic Programming

Intermediate

Implement the `minimumFlipsMonotoneBinary` method that returns the minimum flips needed to make a binary string monotone increasing.

Math Dynamic Programming

Guru

Implement the `burstBalloonsMaxCoins` method that returns the maximum coins obtainable by bursting balloons in the best order.

Math Dynamic Programming

Proficient

Implement the `maxProfitWithCooldown` method that returns the maximum stock profit with a one-day cooldown after selling.

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.

Math Bit Manipulation

Learner

Implement the `subsetsCountByBitmask` method that returns how many subsets can be formed using bitmasking.

Math Bit Manipulation

Proficient

Implement the `maximumXorPairSimple` method that returns the maximum XOR value obtainable from any pair.

Math Bit Manipulation

Learner

Implement the `hammingDistanceValues` method that returns the number of bit positions where two integers differ.

Math Bit Manipulation

Learner

Implement the `powerOfFourCheck` method that checks whether a number is a power of four.

Math Bit Manipulation

Learner

Implement the `missingNumberXorImportant` method that finds the missing number using XOR logic.

Math Bit Manipulation

Intermediate

Implement the `bitwiseAndRange` method that returns the bitwise AND of all numbers in the given range.

Math Bit Manipulation

Learner

Implement the `reverseBitsSimple` method that returns the integer formed after reversing the bits.

Math Bit Manipulation

Learner

Implement the `countBitsUpToNSum` method that returns the total count of set bits for all numbers from 0 to n.

Math Bit Manipulation

Intermediate

Implement the `singleNumberTwoValuesCount` method that counts the two values that appear once when others appear twice.

Math Bit Manipulation

Learner

Implement the `singleNumberUsingXor` method that returns the number that appears once using XOR logic.