Visualize long division with ASCII art

Question

Write a program that visualizes long division with ASCII art. Input consists of two integers, a numerator and a denominator, using the input format of your choice.

Examples:

1234 ÷ 56:

     22
   ----
56|1234
   112
   ---
    114
    112
    ---
      2

1002012 ÷ 12:

     83501
   -------
12|1002012
    96
   ---
     42
     36
     --
      60
      60
      --
        12
        12
        --

0 ÷ 35

   0
   -
35|0

Rules:

• Use of the programming language's division operator is allowed.
• Use of big integer support is also allowed.
• For consistency:
  • If the quotient is zero, print a single zero at the end of the diving board.
  • If the remainder is zero, do not print it.
  • Do not print leading zeros on any numbers.
• Excess newlines at the end and trailing spaces to the right are allowed.
• Solution with the fewest characters wins.

Limits:

• 0 <= numerator <= 10⁷² - 1
• 1 <= denominator <= 9999999

This implies that the output will never be wider than 80 columns.

Test suite and sample implementation:

You can use long-division.c (gist) to test your program. It is actually a bash script with a C program inside. Tweak it to invoke your program in the test suite. Look at the C code at the bottom to see the reference implementation. Please let me know if there are any problems with the sample program or test suite.

$ ./long-division.c 10 7
   1
  --
7|10
   7
  --
   3
$ ./long-division.c
PASS 1234 ÷ 56
PASS 1002012 ÷ 12
PASS 1 ÷ 1
--- snip ---

Score: 35 / 35
All tests passed!

Edit: By request, I put the test suite input and expected output into text files (gist). Sample usage (bash):

cat input | while read nd; do
    ./program $nd |
        sed 's/\s*$//' | sed -e :a -e '/^\n*$/{$d;N;};/\n$/ba'
done > output

diff -u expected output

The weird sed commands filter out trailing newlines and spaces from the program output.

Answer 1

Python 3, 284 257 characters

div.py

n,t=input().split()
d=int(t)
l=lambda x:len(str(x))
s=l(n)
def p(x):print(' '*(l(d)+s-l(x)+1)+str(x))
p(int(n)//d)
p('-'*s)
p(t+'|'+n)
s=z=f=0
while t:
 try:
  while z<d:z=z*10+int(n[s]);s+=1
 except:t=0
 if z*f:p(z)
 if t:f=1;t=z//d*d;p(t);p('-'*l(z));z-=t

Usage: python3 div.py
Input: from keyboard

test.py

import sys
sys.stdin=open('input'); sys.stdout=open('output','w')
for line in open('input'): exec(open('div.py').read())

output matches expected

Versions:
 1. 284
 2. 257: s,z,f=0,0,0→s=z=f=0; z and f→z*f; better looping; removed a few newlines.

Answer 2

Haskell, 320 characters

l=length
(®)=replicate
p!v=p&show v
p&s=(p-l s)®' '++s
0§_=[];_§l=l
d[m,n]=l c!(read m`div`e):l c&(l m®'-'):c:drop 1(g 0(map(toInteger.fromEnum)m)$1+l n)where
 e=read n;c=n++'|':m
 g r(d:z)p=i§[o!k,o!(i*e),o&(l(show k)®'-')]++g j z o where k=r*10+d-48;(i,j)=k`divMod`e;o=1+p
 g r[]p=r§[p!r]
main=interact$unlines.d.words

Passes all tests. While is this pretty golf'd -- I think there is still yet more to be done here...

---

• Edit: (344 -> 339) delay read calls, which reduces need to call show, enough that abbreviating show as s isn't worth it.
• Edit: (339 -> 320) rewrote string field formatting functions

Answer 3

JavaScript (400 394 418)

function d(n,d){t=parseInt;p=function(v){return(s+v).substring(v.length)};a=function(v,c){return v.replace(/\d/g,c)};w='\n';q=b=o=c=e='';s=a(d,' ')+' ';f=true;i=-1;z='0';while(++i<n.length){s+=' ';if(t(c+=n[i])>=t(d)){q+=r=Math.floor(t(c)/t(d));o+=(!f?p(c)+w:e)+p(''+r*t(d))+w+p(a(c,'-'))+w;c=t(c)%t(d);f=false}else if(!f){q+=z;}c=(c==0)?e:e+c}return p(!q?z:q)+w+p(a(n,'-'))+w+d+'|'+n+w+o+(q?p(c):e)}

NOTE: As tempting as it looks to shave off a few chars by replacing c=(c==0)? with c=!c?, it is not usable because it causes floating point-related bugs.

http://jsfiddle.net/nLzYW/9/

Sample Execution:

document.writeln("<pre>");
document.writeln(d("1234","56"));
document.writeln();
document.writeln(d("1002012","12"));
document.writeln();
document.writeln(d("0","35"));
document.writeln();
document.writeln(d("123000123000123","123"));
document.writeln("</pre>");

Edit 1: Minor bug fixes, numerous code optimizations.

Edit 2: Fix bug with 1/7 generating extra output.

Answer 4

AWK, 422 bytes

I think it took me over a week to solve this problem.

function l(x){return length(x)}{P=9(d=$2);gsub(".",FS,P);N=l(L=n=$1);gsub(".","-",L);O(0,q=int($1/$2));Q=l(q);print P L RS d"|"n}function O(i,x){printf"%"l(d)+N-Q+1+i"d\n",x}m=substr(q,1,1)*d{for(i=1;i<=Q;){O(i,m);print P substr(L,1,N-Q+1);for(_=l(j=n)-l(n-=m*10**(Q-i));_--;)P=P FS;if(!n)exit;match(q,".0*");i+=R=RLENGTH;sub(".{"R"}",E,q);b=q+0?substr(n,1,M=l(m=substr(q,1,1)*d)):n;if(b<m)b=substr(n,1,M+1);O(i-(i>Q),b)}}

Try it online!

Usage

• Input is given from STDIN, as single line.
• Two natural numbers are on same line.
• Output is returned to STDOUT.
• This program does never handle overflow; fails on huge values.
• This program does not handle multiple lines of input correctly; only the first line is handled correctly.

Formatted

function l(x){
  return length(x)}
{
  P=9(d=$2);gsub(".",FS,P);
  N=l(L=n=$1);gsub(".","-",L);
  O(0,q=int($1/$2));
  Q=l(q);
  print P L RS d"|"n}
function O(i,x){
  printf"%"l(d)+N-Q+1+i"d\n",x}
m=substr(q,1,1)*d{
  for(i=1;i<=Q;){
    O(i,m);
    print P substr(L,1,N-Q+1);
    for(_=l(j=n)-l(n-=m*10**(Q-i));_--;)
      P=P FS;
    if(!n)
      exit;
    match(q,".0*");
    i+=R=RLENGTH;
    sub(".{"R"}",E,q);
    b=q+0?substr(n,1,M=l(m=substr(q,1,1)*d)):n;
    if(b<m)
      b=substr(n,1,M+1);
    O(i-(i>Q),b)}}

Answer 5

Javascript: (372)

function g(a){for(var c="",e=0;e<a;e++)c=" "+c;return c}function i(a,c){for(var e=a+"/"+c+"\\",j=(""+c).split(""),k="",d=0,b=0;b<j.length;b++){d*=10;d+=parseInt(j[b],10);var f=d>9?b-1:b,h=0;h=Math.floor(d/a);d%=a;f=g(f+a.toString().split("").length);f+=h*a+"\n"+g(b+a.toString().split("").length)+"--\n"+g(b+a.toString().split("").length)+d+"\n";k+=f;e+=h}return e+"\n"+k}

Invoke by using i(divider,number). Codegolfed JS: http://jsfiddle.net/puckipedia/EP464/ Ungolfed (dutch) JS: http://jsfiddle.net/puckipedia/M82VM/

Returns the long division (in dutch format as i learned it):

5/25\05
 0
 --
 2
 25
  --
  0

Testcase:

document.write("<pre>"+i(5,25)+"</pre>");
document.write("<pre>"+i(7,65669726752476)+"</pre>");