ASCII-visualize a graph

APL (171 166 162 chars, all bonuses: 999 - 171 166 162 + 20 + 20 + 200 = 1068 1073 1077)

This is the longest golfed APL program I've written so far. This might be slightly cheating, but there's nothing in the question that actually disallows this. What I'm doing is putting all the nodes on a vertical line and drawing the graph as an arc diagram. It is obviously still a graph though.

It still took me a few hours.

V←' '⍴⍨99,⍨2×⍴P←∪,C←(2,⍨2÷⍨⍴G)⍴G←G/⍨⎕A∊⍨G←⍞⋄V[2×⍳⍴P;50]←P⋄M←1⋄G←⍴D←{⍵[⍋⍵]}¨↓P⍳C⋄{V[A B←⍵;L←50+M×⌽⍳G]∘←'-'⋄V[A+⍳B-A;⊃L]∘←'|'⋄V[⍵;⊃L]∘←'+'⋄M×←¯1⋄G-←1}¨2×D[⍒|-/↑D]⋄V

The nodes must be single uppercase letters, so it supports 26 nodes maximum. It can handle crossed lines, and each node can have as many connections as the display will handle.

Example output:

A,B C,A C,D

      +-A--+                                              
      |    |                                              
      +-B  |                                              
           |                                              
        C+-+                                              
         |                                                
        D+   

A,B C,A B,A A,D A,E F,G C,G

          +--A-+-+-+                                           
          |    | | |                                           
          |  B-+ | |                                           
          |      | |                                           
        +-+--C   | |                                           
        |        | |                                           
        |    D---+ |                                           
        |          |                                           
        |    E-----+                                           
        |                                                      
        |   +F                                                 
        |   |                                                  
        +---+G                                                 


 T,H E,Q U,I C,K B,R O,W N,F O,X J,U M,P S,O V,E R,T H,E L,A Z,Y D,O G,S

               +---+----------T                                                 
               |   |                                                            
               |   +-------+--H                                                 
               |           |                                                    
               |           +--E---------+-------+                               
               |                        |       |                               
               |              Q---------+       |                               
               |                                |                               
               |     +--------U---------------+ |                               
               |     |                        | |                               
               |     +--------I               | |                               
               |                              | |                               
               |              C-------+       | |                               
               |                      |       | |                               
               |              K-------+       | |                               
               |                              | |                               
               |       +------B               | |                               
               |       |                      | |                               
               +-------+------R               | |                               
                                              | |                               
             +----------------O-----+-----+-+ | |                               
             |                      |     | | | |                               
             |                W-----+     | | | |                               
             |                            | | | |                               
             |           +----N           | | | |                               
             |           |                | | | |                               
             |           +----F           | | | |                               
             |                            | | | |                               
             |                X-----------+ | | |                               
             |                              | | |                               
             |                J-------------|-+ |                               
             |                              |   |                               
             |                M---+         |   |                               
             |                    |         |   |                               
             |                P---+         |   |                               
             |                              |   |                               
             |   +------------S-------------+   |                               
             |   |                              |                               
             |   |            V-----------------+                               
             |   |                                                              
             |   |            L-+                                               
             |   |              |                                               
             |   |            A-+                                               
             |   |                                                              
             |   |           +Z                                                 
             |   |           |                                                  
             |   |           +Y                                                 
             |   |                                                              
             +---|------------D                                                 
                 |                                                              
                 +------------G                                                 

Python, 195 chars, score = 999 - 195 + 20 + 200 + 20 = 1044

R=raw_input()
V=' '.join(set(R)-set(' ,'))
S=' '*len(V)
for e in R.split():x,y=sorted(map(V.index,e[::2]));print S[:x]+'+'+'-'*(y-x-1)+'+'+S[y+1:];S=S[:x]+'|'+S[x+1:y]+'|'+S[y+1:];print S
print V

Each edge gets a row. S is a string with the vertical connections we need to keep as we build the graph.

Here are some sample input/output:

A,B C,A B,A A,D A,E F,G C,G
+---+        
|   |        
+-+ |        
| | |        
+---+        
| | |        
+-------+    
| | |   |    
+-----+ |    
| | | | |    
| | | | | +-+
| | | | | | |
| +-------+ |
| | | | | | |
A C B E D G F

and stolen from marinus:

T,H E,Q U,I C,K B,R O,W N,F O,X J,U M,P S,O V,E R,T H,E L,A Z,Y D,O G,S
                +-----------------------+          
                |                       |          
      +-----------------------+         |          
      |         |             |         |          
      |       +-----------------------+ |          
      |       | |             |       | |          
  +---------------+           |       | |          
  |   |       | | |           |       | |          
  | +-------------------------------+ | |          
  | | |       | | |           |     | | |          
  | | |       | | |       +---------------+        
  | | |       | | |       |   |     | | | |        
  | | |     +---------------+ |     | | | |        
  | | |     | | | |       | | |     | | | |        
  | | |     | | | |       +---------------------+  
  | | |     | | | |       | | |     | | | |     |  
  | | |     | | | | +-----------------+ | |     |  
  | | |     | | | | |     | | |     | | | |     |  
  | | |     | | | | | +---------+   | | | |     |  
  | | |     | | | | | |   | | | |   | | | |     |  
  | | |     | | | | | |   +-------+ | | | |     |  
  | | |     | | | | | |   | | | | | | | | |     |  
  | | +-------------------------------------+   |  
  | | |     | | | | | |   | | | | | | | | | |   |  
  | | |     | | | | | |   | | | | | +---+ | |   |  
  | | |     | | | | | |   | | | | | | | | | |   |  
  | | +---------+ | | |   | | | | | | | | | |   |  
  | | |     | | | | | |   | | | | | | | | | |   |  
+-----------------------+ | | | | | | | | | |   |  
| | | |     | | | | | | | | | | | | | | | | |   |  
| | | |     | | | | | | | | | | | | | | | | | +---+
| | | |     | | | | | | | | | | | | | | | | | | | |
| | | | +-----------------+ | | | | | | | | | | | |
| | | | |   | | | | | | | | | | | | | | | | | | | |
| | | | | +-----------------------+ | | | | | | | |
| | | | | | | | | | | | | | | | | | | | | | | | | |
A C B E D G F I H K J M L O N Q P S R U T W V Y X Z

Python 3, 168 chars, Score = 999- 168 + 240 = 1071

Just shortening Keith Randalls great answer.

  1. In Python 3, print is a function, and therefore can be abbreviated by p=print. Saves 3 * (4 - 1) - 8 = 1 character.

  2. In Python 3, input is used instead of raw_input, saves 4 characters.

  3. Instead of ' '*len(V) you can use ' '*80 (or something similar). This leads to an increased number of trailing spaces, but who cares... if it saves another 4 characers!

  4. Now it gets interesting: Instead of strings, use lists! This makes the updating of S much easier, but complicates printing somewhat. I'll call the list T so I'll not confuse it with the string S from marinus.

  5. Let's start by turning the vertices into a list, not a space-seperated string, which saves 4 characters. The output line T has to become a list (T=[' ']*40), which costs 2 characters.

  6. The printing of the current line T becomes 5 characters longer: I need brackets to concatenate the lists of strings correctly, I need two more - characters (because x and y are only about half as large now), and I need a * to make the print function take the elements of the list as seperate arguments and print them out seperated by spaces (and not as a list!). (This step was hard.)

  7. The current line can be updated with a simple T[x]=T[y]="|" instead of S=S[:x]+'|'+S[x+1:y]+'|'+S[y+1:], which saves 19 characters.

  8. For printing T again, and for the final spaced printing of the vertices, asterisks are needed, which costs 2 characters.

  9. And just while I am typing this, I see that there is no harm in having an unconnected invisible vertex (' '). This allows to create the set of vertices much shorter, saving 4 more characters.

Altogether, the saving is 1 + 4 + 4 + 4 - 2 - 5 + 19 - 2 + 4 = 27.

R=input()
p=print
V=list(set(R)-{','})
T=[' ']*40
for e in R.split():x,y=sorted(map(V.index,e[::2]));p(*T[:x]+["+"+"--"*(y-x-1)+"-+"]+T[y+1:]);T[x]=T[y]="|";p(*T)
p(*V)

Example showing the effect of 9.: input A,B A,C leads to output

+-----+                                                                        
|     |                                                                        
+---+ |                                                                        
|   | |                                                                        
A   C B