Haskell, 424 chars
Current char count: 424 430 451 466 511 515 516 518 525 532 541 545 550 556 569 571 577 582 586 592.
import List
x%c=[(i,c)|i<-x]
l k p q|p>q=l k q p|True=head[[p,p+j..q]%c|m<-zip[k-1,k,k+1,1]"/|\\-",let (j,c)=m,mod(q-p)j==0]
w=map snd
q(k,m,x)z=w$sort$nubBy((==)&fst)$x%'+'++(concat$zipWith(l k)x$tail x)++z%'\n'++[1..m]%' '
r(z,m,x)=q(last z,m-1,w$sort x)z
u[(m,_)]n x=(-m::Int,n):x;u _ _ x=x
t(z,n,x)s|s=="\n"=(n:z,n+1,x)|True=(z,n+length s,u(reads s)n x)
y&x=(.x).y.x
main=interact$r.foldl t([],1,[]).groupBy((&&)&(>' '))
This version takes a lot of inspiration from the original Haskell entry below, but makes some significant changes. Most importantly, it represents image locations with a single index, not a pair of coordinates.
There are some changes:
- The input must now have all lines padded to the same length (allowed by the rules.)
- No longer needs either language extension
Original version:
(Needs -XTupleSections, and maybe -XNoMonomorphismRestriction)
import List
b=length
f=map
g=reverse
a(x,y)" "=(x,y+1)
a(x,y)z=([y,read z]:x,y+b z)
x%y=[min x y+1..max x y-1]
j([x,y],[w,z])|y==z=f(,'-')$f(y,)$x%w|x==w=f(,'|')$f(,x)$y%z|(y' '))$lines z;e=tail?f g$zipWith(f.(:))[1..]$f(fst.foldl a([],1))d
main=interact r
Explanation:
(1) d=...: Splits the input into spaces and numbers, e.g.
z = " 6 5\n\n1 2\n\n 4 3\n\n 7"
=> d = [[" ","6"," "," ","5"],[],["1"," "," "," "," "," "," "," ","2"],[],[" "," "," "," ","4"," "," "," ","3"],[],[" ","7"]]
(2) e=...: Converts d into a list of (y, x) coordinates for each number.
e = [[1,3],[9,3],[9,5],[5,5],[5,1],[2,1],[2,7]]
--- // 1 2 3 4 5 6 7
(3)
[((y,x),k x)|...] is an empty board. (k returns a space or a \n depending on the x-coordinate.)[((y,x),'+'))|...] are the plus signs at the numbers.(f j$zip e$tail e) are the lines connecting the numbers. (j maps a pair of coordinates into a list of (coordinate, character) which represents a line.)
These 3 components are concatenated and filtered to form the actual output. Note that the order is important, so that nubBy(...).g can only keep the last character in the same location.
