Unfortunetly thats true, instruction is contradictory in one place

"negative-base number being one digit longer than its positive-base equivalent"
...
"For example, the representation for 6 is '11010' and -6 is '1110'."

Negativ is shorter here, so people are disoriented. I am.

Same here, I don't get the instructions. Sry

Well done ;-)

I should go to bed, so many suggestions for the time being.

another wrong(maybe) is there: !value || last !== value

I don't know !value mean, but I know if value==0 what will happen ;-)

another wrong is there:var value = sorted.shift();

if you used shift(), your array length will changed, and you use for loop, i<=len should got some undefined value

another wrong is there: for(i=0; i<=len; i++){

i<=len should be i<len

sorted[len] ====== undefined

I think it because you modified the original array.

the first line maybe write like this:var sorted=A.slice().sort(doSort)

I can't sunmit your code now, CW running slowly...

paste your code here is a good idea ;-)

Don't forget mark as having spoiler content