Nice solution! It's elegant and easy to read!

what does "stack has an initial value of zero" mean? I interpreted "value of zero" as they each have one zero element but it really means that stacks have an initial size of zero.

This is false, the stacks are indeed initialized with a single 0 each

I have an error too on this particular test.
For me it is totally wrong. There are only 0(in a_vector) and 10000 (in b_vector) left
0^2 != 100000, but the test says it should be true...

Current test case I am stuck on:

##>>><.>+<>,935<+#,408+<.#<
A: 384,1,0,0,0,0,0,0,0,365,202,18,445
B: 3,105,485,2
C: 0,0,2,601,0,0,0,1
Expected: '3650', instead got: '0601'

(top of stack is the far right)

Based on the initial ## the moves operate on stack C so I dont see how 3 ever gets to be the first number in the output.

Wow, details are very misleading on this one on two points:

1. stack values persist across calls to read
2. what does "stack has an initial value of zero" mean? I interpreted "value of zero" as they each have one zero element but it really means that stacks have an initial size of zero.

Having fun with figuring out the details through trial and error though....definitely a great kata.

Glad to hear that you enjoyed it; don't forget to check out other Kata I have authored :D

OMG thats evil

Implementing a simple TM in JavaScript was fun. One of my favorite kata so far. Looking forward to the next 2.

In C++, I printed the input vectors and they show up on all but test6 (the only one I am failing!).
Why no input printed on this test case?

Anyone who used bit manipulation?

Surprised nobody else seems to be using bitwise AND in C/C++. It was my first thought.