Math & Geometry Problems

Math problems in coding interviews don't test deep mathematics — they test whether you can spot the right insight quickly. Common subtopics include modular arithmetic (avoid overflow, compute large powers), prime factorization, GCD and LCM, base conversion, and matrix-inspired transformations like rotating a 2D array in place.

The recurring trick is to avoid the brute-force computation entirely. Computing factorials? Use modular arithmetic. Counting primes? Sieve of Eratosthenes. Power of two? Bit trick. Pow(x, n)? Fast exponentiation. Each of these reduces an O(n) or O(n²) approach to O(log n) or O(√n) with a small algebraic insight.

The Ratta math track covers Pow(x, n), Sqrt(x), Reverse Integer, Excel Sheet Column Number, Happy Number, and the matrix-rotation family. Solutions in C++, Java, Python, and Go highlight the math identity that makes each problem easy and explain why the brute force is unnecessary.