No, I don't, idea is simple, but I have a problem: I get MLE of #15, and I can't fix it. I'we tried all ways of graph representation, but I always get MLE #15. Can someone please help me? Here is part of my code that uses the memory, the working part is eliminated:

type
  TEdge=record
          i,j:integer
        end;
var
  g:array[1..100001] of TEdge;
  st,deg:array[0..1001] of integer;
  sol:array[1..1000] of integer;
  n,m,i,k:integer;
procedure sort(l,r:integer);
var
  i,j:integer;
  k,t:TEdge;
begin
  i:=l;
  j:=r;
  k:=g[(i+j) div 2];
  while i<=j do
    begin
      while (g[i].i<k.i) or ((g[i].i=k.i) and (g[i].j<k.j)) do inc(i);
      while (k.i<g[j].i) or ((k.i=g[j].i) and (k.j<g[j].j)) do dec(j);
      if i<=j then
        begin
          t:=g[i];
          g[i]:=g[j];
          g[j]:=t;
          inc(i);
          dec(j)
        end
    end;
  if i<r then sort(i,r);
  if l<j then sort(l,j)
end;
begin
  assign(input,'');
  reset(input);
  readln(n,m);
  for i:=1 to n+1 do
    begin
      deg[i]:=0
    end;
  for k:=1 to m do
    begin
      readln(g[k].i,g[k].j);
      inc(deg[g[k].j])
    end;
  g[m+1].j:=0;
  g[m+1].i:=0;
  for i:=1 to n do
    read(sol[i]);
  sort(1,m);
  close(input);
// working part goes here, cut because of fourth rule.....
end.

When i first time solution this problem o has WA and really don't understand WHY.
But now i write a simple programm 20 lines and get AC.

Sorry for my English.

Edited by author 01.04.2005 20:05

Very simple...

Edited by author 01.04.2005 20:08

Pls dont do any sort, just check for prerequisites of subjects in the left side of order for given subject. I think you should be able to get solution in O(N+M).