Code Challenges

Get better at coding with practice problems.

Coding Challenges

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

Math Number Theory Combinatorics

Learner

Implement the `integerSquareRootFloor` method that returns the floor value of the square root of an integer.

Math Dynamic Programming Tabulation

Intermediate

Implement the `maximumProductCutting` method that finds the maximum product obtainable by cutting an integer into parts.

Math Dynamic Programming Matrix Tabulation

Learner

Implement the `uniquePathsInGrid` method that counts paths from the top-left cell to the bottom-right cell in a grid.

Array Math Dynamic Programming Tabulation

Proficient

Implement the `minimumCoinsToMakeAmount` method that finds the minimum number of coins required to make the target amount.

Array Math Dynamic Programming Tabulation

Proficient

Implement the `countWaysToMakeAmount` method that counts how many combinations can make the target amount using coins.

Math Dynamic Programming Memoization Tabulation

Learner

Implement the `fibonacciDP` method that returns the nth Fibonacci number using dynamic programming.

Math Number Theory Simulation

Intermediate

Implement the `isHappyNumber` method that checks whether repeatedly summing the squares of digits reaches 1.

Math Number Theory

Learner

Implement the `isPerfectNumber` method that checks whether a number is equal to the sum of its proper divisors.

Math Combinatorics

Intermediate

Implement the `nCrValue` method that calculates the binomial coefficient value nCr.

Math Number Theory

Learner

Implement the `isArmstrongNumber` method that checks whether a number is equal to the sum of its digits raised to the digit count.

Math Number Theory Bit Manipulation

Intermediate

Implement the `fastPowerModulo` method that calculates base raised to exponent under a given modulo efficiently.

Math Number Theory

Learner

Implement the `lcmOfTwoNumbers` method that returns the least common multiple of two numbers.

Math Number Theory

Learner

Implement the `gcdOfTwoNumbers` method that returns the greatest common divisor of two numbers.

Math Number Theory

Intermediate

Implement the `countPrimeNumbersUpToN` method that counts all prime numbers from 2 up to the given number.

Math Number Theory

Learner

Implement the `isPrimeNumber` method that checks whether the given number is prime.

Array Math Number Theory

Learner

Implement the `findMissingNumberFromOneToN` method that finds the missing value from a sequence that should contain numbers from 1 to n.

Math Dynamic Programming

Proficient

Implement the method `coinChangeMinCoins` that returns the minimum number of coins needed for an amount.

Learner

Implement the method `productSign` that returns the sign of the product of an integer array.

Math Conversion

Beginner

Implement the method `celsiusToFahrenheit` that converts Celsius to Fahrenheit.