hoest21 was a series of task over the span of 4 weeks. These are my solutions for them. Leaderboard is available on kattis.

I've tried my best to optimize the runtime of the solutions. I use a variant of the following method in almost all solutions.

static int readNum() throws java.io.IOException {
    int num = 0, b;
    while ((b = System.in.read()) != '\n' && b != ' ' && b != -1)
        num = num * 10 + b - '0';
    return num;
}

What it does is read until the next newline, space, or EOF and return what was read as an int. Using System.in for IO is faster than wrapping it in the slow (but handy) java.util.Scanner.

When applicable, I've included a single sample input in a samp.in file. Testing the solution can be done by running java main.java < samp.in, although one should prefer javac main.java && java <ClassName> < samp.in.