Advent of Code 1.1

commented.bf

>> Make two temp cells
+++++[>++++++++<-] Put 40 (which is '(') in the fourth cell
, Read in the first byte of input
[
Compare the input to 40
[<+>-]+
>[<<-<+>>>-]
<<<[>>>+<<<-]
>[>-<[-]]
If/else the comparison
<[-]+
>[-]
>[
 If the input was a (
 >>+ Add one to the increments
 <<<<-
 >>[<+>-]
]
<[>+<-]
<[
 If the input was a )
 >>>>>+ Add one to the decrements
<<<<<-]
>>[-],]
We've counted all of the increments and decrements so let's copy the increments to the cell to the right of the decrements
<<[-]
>>>>>>[-]
<<[>>+<<<<<<+>>>>-]
<<<<[>>>>+<<<<-]

Now it's time to find out which is larger
>>>>>>>[-]
>[-] >[-]+ >[-] <<
<<<[>>+ >+ <<<-]
>>>[<<<+ >>>-]
<<<<[>>>>+ <<<<-]
>>>>[>-]> [< <<<<+ >>>[-] >>->]<+<
<[>- [>-]> [< <<<<+ >>>[-]+ >>->]<+< <-]
The fifth cell tells us whether the decrements are larger than the increments
So let's check if that's true
<<<<<<<[-]+
>[-]
>>>[

 The decrements are larger so we subtract them from the increments after outputting a minus sign
 >>>>[-] Move over to temp3 and clear it
 >[-]< Move to temp4 and clear it and move back to temp3
 +++++[>+++++++++<-]>.[-] Output a minus and clear the cell
 <<<<< Move back to x
 this is z equals z minus y
 >>>[-]
 <[<->>+<-]
 >[<+>-]

 We have now done the subtraction and all that's left to do is output the number at z
 << Move to z

 Copy the number to print out to temp4
 >>>[-]
 >[-]
 <<<<[>>>>+<+<<<-]
 >>>[<<<+>>>-]

 <<<<<-
 >>>>[<<<+>>>-]
]
<<<[>>>+<<<-]
<[

 Increments are larger than decrements so subtract them
 >>>>>>>[-]
 <<[>->+<<-]
 >>[<<+>>-]

 < Move to z
 Copy number to temp4
 >>[-]
 >[-]
 <<<[>>>+<+<<-]
 >>[<<+>>-]>

<<<<<<<<<-]

>>>>>>>>> Move to temp4
 Print out the number
[>>+>+<<<-]>>>[<<<+>>>-]<<+>[<->[>++++++++++<[->-[>+>>]>[+[-<+>]>+>>]<<<<<]>[-]
++++++++[<++++++>-]>[<<+>>-]>[<<+>>-]<<]>]<[->>++++++++[<++++++>-]]<[.[-]<]<

nailedIt.bf

>>+++++[>++++++++<-],[[<+>-]+>[<<-<+>>>-]<<<[>>>+<<<-]>[>-<[-]]<[-]+>[-]>[>>+<<<<->>[<+>-]]<[>+<-]<[>>>>>+<<<<<-]>>[-],]<<[-]>>>>>>[-]<<[>>+<<<<<<+>>>>-]<<<<[>>>>+<<<<-]>>>>>>>[-]>[-]>[-]+>[-]<<<<<[>>+>+<<<-]>>>[<<<+>>>-]<<<<[>>>>+<<<<-]>>>>[>-]>[<<<<<+>>>[-]>>->]<+<<[>-[>-]>[<<<<<+>>>[-]+>>->]<+<<-]<<<<<<<[-]+>[-]>>>[>>>>[-]>[-]<+++++[>+++++++++<-]>.[-]<<[-]<[<->>+<-]>[<+>-]>[-]>[-]<<<<[>>>>+<+<<<-]>>>[<<<+>>>-]<<<<<->>>>[<<<+>>>-]]<<<[>>>+<<<-]<[>>>>>>>[-]<<[>->+<<-]>>[<<+>>-]>[-]>[-]<<<[>>>+<+<<-]>>[<<+>>-]<<<<<<<<-]>>>>>>>>>[>>+>+<<<-]>>>[<<<+>>>-]<<+>[<->[>++++++++++<[->-[>+>>]>[+[-<+>]>+>>]<<<<<]>[-]++++++++[<++++++>-]>[<<+>>-]>[<<+>>-]<<]>]<[->>++++++++[<++++++>-]]<[.[-]<]<