Tunnels

/usr/bin/ld.bfd: warning: output/link.res contains output sections; did you forget -T?

  Const MAX_N = 100000;
  
  Type tEdge = record
    dest , next : LongInt;
  end;
  
  
  var E : array [ 1 .. 2*MAX_N ] of tEdge; 
      ee : LongInt;
      Link_In , Link_Out : array [ 1 .. MAX_N ] of LongInt;
  
  procedure addEdge ( u , v : LongInt ) ; 
  begin
    Link_Out[u] += 1;
    
    // u <- v back edge
    inc ( ee ) ; 
    E[ee].dest := u;
    E[ee].next := Link_In[v];
    Link_In[v] := ee;
  end;
  
  
  var Q : array [ 1 .. MAX_N ] of LongInt;
      qq : LongInt = 0 ; 
  
  procedure Push ( x : LongInt ) ; 
  begin
    inc ( qq ) ; 
    Q[qq] := x;
  end;
  
  procedure DFS ( v : LongInt ) ;
    var tmp : tEdge;
  begin
    
    if ( Link_In[v] = 0 ) then
      exit();
    
    tmp := E[  Link_In[v] ];
    
    //writeLn ( v , ' -> ' , tmp.dest ); 
    DFS ( tmp.dest );
    
    dec ( Link_Out [ tmp.dest ] );
    if ( Link_Out[tmp.dest] = 0 ) and ( Link_In[tmp.dest] > 0 ) then
      Push ( tmp.dest );
    
    Link_In[v] := tmp.next;
  end;


  var N , M : LongInt;
      u , v , i , ans : LongInt;
begin
  
  ans := 0 ; 
  
  readLn ( N , M ) ; 
  
  for i := 1 to M do
  begin
    readLn ( U , V ) ; 
    addEdge ( u , v ) ; 
  end;
  
  
  for i := 1 to N do
    if ( Link_Out[i] = 0 ) and ( Link_In[i] > 0 ) then
      Push ( i ) ; 
  
  i := 1;
  while ( i <= qq ) do
  begin
    while ( Link_In[ q[i] ] > 0 ) do
    begin
      DFS ( q[i] );
      inc ( ans ) ; 
      //writeLn ( 'END ' ) ; 
    end;
    inc ( i ) ; 
  end;
  
  
  writeLn ( ans ) ; 
  
  
end.

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED