Code Challenges

Get better at coding with practice problems.

Coding Challenges

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

Start with beginner challenges

Beginner

Implement the method `sumOfSquares` that returns the sum of squares from 1 to n.

Learner

Implement the method `fibonacci` that returns the nth Fibonacci number.

Math Number Theory

Learner

Implement the method `gcd` that returns the greatest common divisor of two integers.

Beginner

Implement the method `calculateCircleArea` that takes the radius of a circle as a `float` and returns its area.

Beginner

Implement the method `sumDigits` that takes an integer as input and returns the sum of its digits.

Math Decision Making

Beginner

Implement the method `isEven` that takes an integer as input and returns `true` if the number is even, and `false` if it is odd.

Learner

Implement the method `factorial` that takes a non-negative integer as input and returns its factorial.

Loop Array Math

Learner

Implement the method `sumArray` that calculates and returns the sum of all integers in an input array.