【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=110000000000;
var vet,next,len,w:array[1..2100000]of longint;
    dis:array[1..1100000]of int64;
    a:array[1..1100000]of int64;
    b:array[1..1100000]of longint;
    inq:array[1..1000000]of boolean;
    head:array[1..1000000]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>1)and(a[k]<a[k div 2]) do
 begin
  swap(a[k],a[k div 2]);
  tt:=b[k]; b[k]:=b[k div 2]; b[k div 2]:=tt;
  k:=k div 2;
 end;
end;

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

 while k+k<=m do
 begin
  t:=k+k;
  if (t+1<=m)and(a[t+1]<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:=1; w[1]:=n;
 while x<>1 do
 begin
  e:=head[x];
  while e<>0 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 2 do write(w[i],' ');
 write(w[1]);
end;

procedure dijkstra;
var m,u,e,v:longint;
begin
 fillchar(dis,sizeof(dis),$7f);
 fillchar(inq,sizeof(inq),false);
 m:=1; a[1]:=0; b[1]:=1; dis[1]:=0;
 while a[1]<oo do
 begin
  u:=b[1]; a[1]:=oo; shiftdown(1,m);
  if inq[u] then continue;
  e:=head[u]; inq[u]:=true;
  while e<>0 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(-1)
  else print;
end;

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