I just solved the V-Subtree problem on AtCoder DP Contest, and after solving it, I couldn't find anyone who solved it iteratively, so I decided to share my code with you :)

My code (without my template)

My idea was that, to do a topological sort iteratively, I thought I had to use Kahn's algorithm. When I found that I was getting a wrong answer, I tried to find the problem, and it turned out that the tree was undirected. After some deep thinking, I realized that I could treat the tree as directed, so I sorted the elements by their distance from the root (any root can be taken since it's undirected). Then, I went on to write the answer code :)

Hello Codeforces!!

A few days ago, I wrote a code for BigInt and BigFloat classes and i would like to share it with you for feedback and improvement. For the code Press here.

Note: My BigFloat class stores numbers as a numerator and denominator to efficiently represent fractions like (1/3) without wasting data.

You can use functions like floor(object, n), ceil(object, n), or round(object, n) to extract the first n decimal places or convert the object to a string with a specified precision using str(n).

I've also implemented all comparison operations for BigFloat objects.

Note: The modulus operation for BigFloat currently calculates the modular inverse of the number. While this is interesting, you might also consider offering standard modulus behavior for users.

The Important Operations is

Multiplication: O((n + m) * log(n + m)) using FFT (Fast Fourier Transform). However, for small values of m, O(n * m) might be faster due to lower constant factors. (Here, n refers to the number of digits in the first number, and m refers to the number of digits in the second number.)

Addition and Subtraction: O(max(n, m)) for efficient handling.

Division and Modulus: O(n * m).

Bitwise Operations: O(n * log(n)).

GCD (Greatest Common Divisor) and LCM (Least Common Multiple): O(n * n * log(n)).

Other Mathematical Functions: I've added ceil, floor, round, abs, sqrt, and cbrt (using Newton's Method) to enhance the functionality of the BigFloat class.

Finally, I would like to thank mostafa133 for his help for this code and TryOmar for training me during the beaver scholarship.