exercism/zig/collatz-conjecture/collatz_conjecture.zig

// Please implement the `ComputationError.IllegalArgument` error.

pub const ComputationError = error{IllegalArgument};

pub fn steps(number: usize) anyerror!usize {
    if (number < 1) return ComputationError.IllegalArgument;

    var count: usize = 0;
    var temp: usize = number;
    while (temp > 1) : (count += 1) {
        if (temp % 2 == 0) {
            temp /= 2;
        } else {
            temp = temp * 3 + 1;
        }
    }

    return count;
}