- Do you know test 4 ?
- Any helpful tests ?
- If not, please pick bugs from my code. My algo: Find minimal, adjacent list, output sorted list. Tks a loooottttttt

Program Prufer_Code;
Type
        pnode = ^node;
        node = Record
         data:Longint;
         next:pnode;
End;

Var     adjList:Array[0..7500] of pnode;
        temp:pnode;
        A,C,minS:Array[0..7500] of Longint;
        n,i,j,s,p,q,m:Longint;
        fi:Text;
Procedure add(k:Longint;var x:pnode);
Var
        y,z:pnode;
Begin
        If (x=nil) then
         Begin
          new(x);
          x^.data:=k;
         End
        Else
         Begin
          new(y);
          y^.data:=k;
          y^.next:=x;
          x:=y;
         End;
End;

Begin

                n:=0;
                While not seekeof do
                 Begin
                  inc(n);
                  Read(A[n]);
                 End;

                For i:=1 to n+1 do
                 Begin
                  inc(C[i]);
                  inc(C[A[i]]);
                 End;
                dec(C[A[n+1]],2);
                p:=0;

                For i:=1 to n+1 do
                 If C[i]=1 then
                  Begin
                   inc(p);
                   minS[p]:=i;
                  End;

                For i:=1 to n do
                 Begin
                  q:=minS[1]; m:=1;
                  For j:=2 to p do
                   If minS[j]<q then
                    Begin
                     q:=minS[j];
                     m:=j;
                    End;
                  j:=q; minS[m]:=99999;


                  add(j,adjList[A[i]]);
                  add(A[i],adjList[j]);
                  dec(C[A[i]]);

                  If C[A[i]]=1 then
                   Begin
                    inc(p);
                    minS[p]:=A[i];
                   End;

                 End;

                For i:=1 to n+1 do
                 Begin
                  FillChar(C,sizeof(C),0);
                  temp:=adjList[i];
                  p:=0;
                  while temp<>nil do
                   Begin
                    inc(C[temp^.data]);
                    temp:=temp^.next;
                   End;
                  Write(i,': ');
                  For j:=1 to 7500 do
                   If C[j]=1 then Write(j,' ');
                  Writeln;
                 End;
End.

I receive Access violation it test 4 too. :(
Do anyone know the test?

I was crashed on this test, because i forget to fill inf in cells of heap, before i start to solve. Also you can try this test:
input: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
output: is obvious

Are you store the double edge but didn't double the edge memory?