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Cod sursa(job #477174)
{$s-}
var a:array[1..3000000]of longint;
buf:array[0..102400]of byte;
n,k,i:longint;
function Select(g,h:longint):longint;
var p,pas,u,i,j,aux:longint;
begin
p:=g;
pas:=1;
while pas<=h-g+1 do begin
u:=p+5*pas;
i:=p;
while u<=h do begin
(*sortarea*)
while i<=u-pas do begin
j:=i+pas;
while j<=u do begin
if a[i]>a[j] then begin
aux:=a[i];
a[i]:=a[j];
a[j]:=aux;
end;
j:=j+pas;
end;
i:=i+pas;
end;
i:=u+1;
u:=u+5*pas;
end;
p:=(pas div 2)+1;
pas:=pas*5;
end;
Select:=p;
end;
function partition(p,q:longint):longint;
var x,i,j,aux:longint;
begin
x:=a[select(p,q)];
i:=p;
j:=q;
repeat
while a[i]<x do inc(i);
while x<a[j] do dec(j);
if i<=j then begin
aux:=a[i];
a[i]:=a[j];
a[j]:=aux;
inc(i); dec(j);
end;
until i>j;
for i:=p to q do if a[i]=x then break;
partition:=i;
end;
function RandSel(p,q,i:longint):longint;
var r,k:longint;
begin
if p=q then RandSel:=a[p]
else begin
r:=partition(p,q);
k:=r-p+1;
if k=i then RandSel:=a[r]
else begin
if i<k then RandSel:=RandSel(p,r-1,i)
else RandSel:=RandSel(r+1,q,i-k);
end;
end;
end;
begin
assign(input,'sdo.in');
reset(input);
settextbuf(input,buf);
assign(output,'sdo.out');
rewrite(output);
read(n,k);
for i:=1 to n do read(a[i]);
write(RandSel(1,n,k));
close(output);
end.