【CF20C】Dijkstra?（DIJKSTRA+HEAP）

没什么可以说的

做dijk+heap模板吧

以后考试时候看情况选择SFPA和DIJKSTRA

 const oo=;
 var vet,next,len,w:array[..]of longint;
     dis:array[..]of int64;
     a:array[..]of int64;
     b:array[..]of longint;
     inq:array[..]of boolean;
     head:array[..]of longint;
     n,m,tot,i,x,y,z,tt:longint;

 procedure add(a,b,c:longint);
 begin
  inc(tot);
  next[tot]:=head[a];
  vet[tot]:=b;
  len[tot]:=c;
  head[a]:=tot;
 end;

 procedure swap(var x,y:int64);
 var t:int64;
 begin
  t:=x; x:=y; y:=t;
 end;

 procedure shiftup(k,m:longint);
 begin
  while (k>)and(a[k]<a[k div ]) do
  begin
   swap(a[k],a[k div ]);
   tt:=b[k]; b[k]:=b[k div ]; b[k div ]:=tt;
   k:=k div ;
  end;
 end;

 procedure shiftdown(k,m:longint);
 var t:longint;
 begin

  while k+k<=m do
  begin
   t:=k+k;
   if (t+<=m)and(a[t+]<a[t]) then inc(t);
   if a[k]>a[t] then
   begin
    swap(a[k],a[t]);
    tt:=b[k]; b[k]:=b[t]; b[t]:=tt;
    k:=t;
   end
    else break;
  end;
 end;

 procedure print;
 var x,m,i,e,v:longint;
 begin
  x:=n; m:=; w[]:=n;
  while x<> do
  begin
   e:=head[x];
   while e<> do
   begin
    v:=vet[e];
    if dis[v]+len[e]=dis[x] then
    begin
     inc(m); w[m]:=v;
     x:=v;
     break;
    end;
    e:=next[e];
   end;
  end;
  for i:=m downto  do write(w[i],' ');
  write(w[]);
 end;

 procedure dijkstra;
 var m,u,e,v:longint;
 begin
  fillchar(dis,sizeof(dis),$7f);
  fillchar(inq,sizeof(inq),false);
  m:=; a[]:=; b[]:=; dis[]:=;
  while a[]<oo do
  begin
   u:=b[]; a[]:=oo; shiftdown(,m);
   if inq[u] then continue;
   e:=head[u]; inq[u]:=true;
   while e<> do
   begin
    v:=vet[e];
    if inq[v] then begin e:=next[e]; continue; end;
    if dis[u]+len[e]<dis[v] then
    begin
     dis[v]:=dis[u]+len[e];
     inc(m); a[m]:=dis[v]; b[m]:=v;
     shiftup(m,m);
    end;
    e:=next[e];
   end;
  end;

  if dis[n]>oo then writeln(-)
   else print;
 end;

 begin
  //assign(input,'1.in'); reset(input);
  //assign(output,'1.out'); rewrite(output);
  readln(n,m);
  for i:= to m do
  begin
   readln(x,y,z);
   add(x,y,z);
   add(y,x,z);
  end;
  dijkstra;
  //close(input);
  //close(output);
 end.