// cliarray.cpp - arrays in the .NET Common Language Runtime

#using <mscorlib.dll>
#using <System.Numerics.dll>

using namespace System;
using System::Numerics::BigInteger;

namespace {
    __declspec(noreturn) void Die(String^ fmt, ...array<Object^>^ a)
    {
        Console::Error->Write(L"{0}: error: ",
            IO::Path::GetFileNameWithoutExtension(
                Environment::GetCommandLineArgs()[0]));
        Console::Error->WriteLine(fmt, a);
        Environment::Exit(1);
    }

    int ParseOrDie(String^ val)
    {
        try {
            auto n = int::Parse(val);
            if (n < 0) Die(L"{0} is negative", n);
            return n;
        }
        catch (FormatException^) {
            Die(L"\"{0}\" isn't an integer", val);
        }
        catch (OverflowException^) {
            Die(L"\"{0}\" looks way too big (or small)", val);
        }
    }

    array<BigInteger>^ GetFactorials(int n)
    {
        if (n < 0) return gcnew array<BigInteger> {};
        auto a = gcnew array<BigInteger> (n + 1);
        a[0] = 1;
        for (int i {1}; i != a->Length; ++i) a[i] = a[i - 1] * i;
        return a;
    }
}

int main(array<String^>^ args)
{
    if (args->Length != 1) {
        Die(L"too {0} arguments (1 needed, {1} passed)",
            args->Length == 0 ? L"few" : L"many", args->Length);
    }

    auto a = GetFactorials(ParseOrDie(args[0]));
    for (int i {0}; i != a->Length; ++i)
        Console::WriteLine(L"{0}! = {1}", i, a[i]);
}