NikolausHaus (c)Udo Liess 1993..1997  ULi971211
      0
      /\
    / 1  \
0: -------- 1:
   |\3  4/|
  2|  \/  |5
   | /  \ |
2: -------- 3:
       6
2:2013546 2:2013645 2:2046315 2:2046513 2:2053146 2:2056413 2:2103546 2:2103645
2:2146305 2:2146503 2:2153046 2:2156403 2:2350146 2:2351046 2:2364015 2:2364105
2:4015326 2:4015623 2:4026315 2:4026513 2:4035126 2:4036215 2:4105326 2:4105623
2:4126305 2:4126503 2:4135026 2:4136205 2:4530126 2:4531026 2:4562013 2:4562103
2:6301245 2:6304215 2:6310245 2:6314205 2:6324015 2:6324105 2:6501423 2:6502413
2:6510423 2:6512403 2:6542013 2:6542103 3:3012456 3:3012654 3:3042156 3:3046512
3:3056214 3:3056412 3:3102456 3:3102654 3:3142056 3:3146502 3:3156204 3:3156402
3:3240156 3:3241056 3:3265014 3:3265104 3:5014236 3:5014632 3:5024136 3:5026314
3:5036214 3:5036412 3:5104236 3:5104632 3:5124036 3:5126304 3:5136204 3:5136402
3:5420136 3:5421036 3:5463012 3:5463102 3:6201354 3:6205314 3:6210354 3:6215304
3:6235014 3:6235104 3:6401532 3:6403512 3:6410532 3:6413502 3:6453012 3:6453102




---------------------------------- c-source ----------------------------------

#include <stdio.h>
struct{int start,end,busy;}way[]=
    {{0,1,0},{0,1,0},{0,2,0},{0,3,0},{1,2,0},{1,3,0},{2,3,0}};
char path[]="       ";
int pointer=0,start=0;
void search(int node)
{
  if(pointer==7)printf("%i:%s ",start,path);
  for(int w=0; w<7; w++)
  {
    if(!way[w].busy)
    {
      int next=-1;
      if(node==way[w].start)next=way[w].end;
      if(node==way[w].end)next=way[w].start;
      if(next!=-1)
      {
        path[pointer++]=w+'0';
        way[w].busy=1;
        search(next);
        way[w].busy=0;
        pointer--;
      }
    }
  }
}
int main()
{
  printf("\nNikolausHaus (c)Udo Liess 1993..1997  ULi971211\n\
      0\n      /\\\n    / 1  \\\n0: -------- 1:\n   |\\3  4/|\n\
  2|  \\/  |5\n   | /  \\ |\n2: -------- 3:\n       6\n");
  for(;start<4;start++)search(start);
  return 0;
}

--------------------------- original pascal source ---------------------------

{$B-}                                                      {        1       }
uses crt;                                                  {       /\       }
const                                                      {     / 2  \     }
  Version='NikolausHaus by Udo Liess DG0KB  Jan 30 1993';  { k1 -------- k2 }
  NachKnoten:array[1..4,1..7] of integer                   {    |\4  5/|    }
    =((2,2,3,4,0,0,0),                                     {   3|  \/  |6   }
      (1,1,0,0,3,4,0),                                     {    | /  \ |    }
      (0,0,1,0,2,0,4),                                     { k3 -------- k4 }
      (0,0,0,1,0,2,3));                                    {        7       }
  WegFrei:array[1..7] of boolean = (true,true,true,true,true,true,true);
  Pointer:integer=1;
var
  StartKnoten,Knoten,WegNr,i:integer;
  Stack:array[1..7,1..2] of integer;
  Ende:boolean;
begin
  clrscr;
  writeln(Version);
  for StartKnoten:=1 to 4 do
    begin
      writeln;writeln('Startknoten ',StartKnoten,' :');
      Ende:=false;
      Knoten:=StartKnoten;
      WegNr:=1;
      repeat
        while (WegNr<=7) and ((NachKnoten[Knoten,WegNr]=0) or not WegFrei[WegNr])
          do inc(WegNr);
        if WegNr<=7
        then
          begin
            WegFrei[WegNr]:=false;
            Stack[Pointer,1]:=Knoten;
            Stack[Pointer,2]:=WegNr;
            inc(Pointer);
            Knoten:=NachKnoten[Knoten,WegNr];
            WegNr:=1;
          end
        else
          begin
            if Pointer=8
            then
              begin
                for i:=1 to 7 do write(Stack[i,2]);
                write('   ');
              end;
            if Pointer=1
            then Ende:=true
            else
              begin
                dec(Pointer);
                Knoten:=Stack[Pointer,1];
                WegNr:=Stack[Pointer,2];
                WegFrei[WegNr]:=true;
                inc(WegNr);
              end;
          end;
      until Ende;
    end;
  repeat until Keypressed;
end.