Visualise long multiplication with ASCII art

Question

The challenge

Write a program that takes two integers from standard input, separated by a comma, and then prints a visualisation of long multiplication of those two integers to standard output.

Eg:

Input

14, 11

Program output

     14
    x11
   _____
     14
    14
  ______
    154

Input

-7, 20

Program output

     -7
    x20
   _____
     00
    14
   _____
   -140

Assume always correct inputs and numbers in the range [-999, 999]

Winning criteria

Shortest code wins!

Answer 1

Perl, 108 chars

Best of breed 108 char solution, incorporating some ideas from Orabig.

($x,$y)=<>=~/[-\d]+/g;printf"%7s
",$_ for$x,x.$y,"-"x7,(map{abs($x*$_).$"x$i++}reverse$y=~/\d/g),"-"x7,$x*$y

Earlier 139 char solution

sub P{sprintf"%*d",@_}
($x,$y)=<>=~/[^,]+/g;$,=$/;
print P(7,$x),"  x".P(4,$y),"-"x7,(map{P 7-$i++,abs$_*$x}reverse$y=~/\d/g),
"-"x7,P 7,$x*$y

Answer 2

Mathematica 213 217 197 193 186 184 193 184 177

Code

a_~g~b_ := 
With[{e = IntegerDigits@b}, Column[Flatten@{a, UnderBar["x " <> IntegerString[921]], 
Table[Row @@ {PadRight[{a Reverse[e][[i]]}, i, " "]}, {i, Length@e}], OverBar[a b]}, 
Alignment -> Right]]

Usage

g[845, 921]

Answer 3

Python, 174 170:

a,b=input();r,s=str(a),str(b);h=len(r+s)*'-';print'\n'.join(["%9s\n%9s\n%9s"%(r,'x'+s,h)]+["%%%ii"%(9-i)%(int(d)%10*a)for i,d in enumerate(s[::-1])]+["%9s\n%9i"%(h,a*b)])

Usage: exactly as requested, run and input the values in standard input.

To see running: http://ideone.com/S8xNb

Output:

     1234
    x5678
 --------
     9872
    8638
   7404
  6170
 --------
  7006652

Thanks to fabiocerqueira and beary605 and David Carraher

Answer 4

Python, 145, another answer with a little bit different output.

Code

a,b=input();h=6*'-';print'\n'.join(["%6i\nx%5i\n%s"%(a,b,h)]+["%%%ii"%(6-i)%(int(d)%10*a)for i,d in enumerate(str(b)[::-1])]+["%s\n%6i"%(h,a*b)])

Usage

just as requested

Output

   999
x  999
------
  8991
 8991
8991
------
998001

To see running: http://ideone.com/mdR18

Answer 5

Perl, 157 151 150 144 141 133 chars :

($x,$y)=<>=~/[-\d]+/g;map{$z=~s/z/ z/g;$z=(abs$x*$_)."z$z"}split//,abs$y;map{printf"%6s
",$_}$x,"x$y",$b="-"x6,(split/z/,$z),$b,$x*$y

Usage :

>echo "-123, 456" | perl mult.pl
   -123
   x456
-------
    738
   615
  492
-------
 -56088