Cod sursa(job #1173871)

Utilizator azkabancont-vechi azkaban Data 21 aprilie 2014 00:02:21
Problema Algoritmul lui Dijkstra Scor 50
Compilator fpc Status done
Runda Arhiva educationala Marime 2.07 kb
Program dijkstra;
type lista = ^celula;
     celula = record
                    nod : longint;
                    cost : longint;
                    pred : lista;
               end;
const INF=10000;
var Lda : array [1..50000] of lista;
    r  :lista;
    H,D: array [1..50000] of longint;
    n,i,a,b,c,v,k,aux1,p,lungime,aux: longint;

begin
   assign(input,'dijkstra.in'); reset(input);
   assign(output,'dijkstra.out'); rewrite(output);
   readln(n,p); aux1:=n;
   for i:=1 to p do begin
                        readln(a,b,c);
                        new(r);
                        r^.nod:=b;
                        r^.cost:=c;
                        r^.pred:=lda[a];
                        lda[a]:=r;
                    end;

   for i:=2 to n do D[i]:=INF;

   H[1]:=1;
   lungime:=1;
   while lungime>0 do begin
                          v:=H[1];
                          r:=lda[v];
                          H[1]:=H[lungime];
                          lungime:=lungime-1;
   while r<>nil do begin
                    if D[v]+r^.cost<D[r^.nod] then begin
                                                      D[r^.nod]:=D[v]+r^.cost;
                                                      lungime:=lungime+1;
                                                      H[lungime]:=r^.nod;
                                                      k:=lungime;
       while (k>1) and (D[H[k]]<D[H[k div 2]]) do begin
                                                       aux:=H[k];
                                                       H[k]:=H[k div 2];
                                                       H[k div 2]:=aux;
                                                       k:=k div 2;
                                                  end;
                                                   end;
                        r:=r^.pred;
                    end;

                   end;
   for i:=2 to aux1 do
                   if D[i]=INF then write(0,' ')
                               else write(D[i],' ');
   close(input);
   close(output);
end.