Cod sursa(job #575376)

Utilizator andreifirstCioara Andrei Ioan andreifirst Data 8 aprilie 2011 11:23:13
Problema Statistici de ordine Scor 0
Compilator fpc Status done
Runda Arhiva educationala Marime 0.78 kb
var v:array [1..3000000] of longint;
    buf1:array[1.. 1 shl 17] of char;
    i, n, k, aux, q:longint;
    f, g:text;

procedure qsort (st, dr, k:longint);
var s, d, p, t:longint;
  begin
  p:=random(dr-st+1)+st;
  aux:=v[p]; v[p]:=v[st]; v[st]:=aux;
  s:=st; d:=dr;
  while s < d do
    begin
    while (v[d]>=aux) and (s<d) do d:= d-1;
    v[s]:=v[d];
    while (v[s]<=aux) and (s<d) do s:= s+1;
    v[d]:=v[s];
    end;
  v[s]:=aux;
  t:=s-st+1;
  if k <= t then qsort (st, s, k)
            else qsort (s+1, dr, k-t);
  end;

begin
assign (f, 'sdo.in'); settextbuf (f, buf1); reset (f);
assign (g, 'sdo.out'); rewrite (g);
randomize;

read (f, n, k);
for i := 1 to n do read (f, v[i]);

qsort (1, n, k);
q:=v[k];
writeln (g, q);

close (f); close (g);
end.