求NOIP提高2004合并果子的标程

program fruit;
const
maxn=10000;
type
data=array[1..maxn] of longint;
var
inf,outf:text;
min1,min2,ans:longint;
m,n,i:integer;
tr:data;
procedure init;
var
i:integer;
begin
fillchar(tr,sizeof(tr),0);
ans:=0;
assign(inf,'fruit.in');
assign(outf,'fruit.out');
reset(inf);
readln(inf,n);
m:=n;
for i:=1 to n do
read(inf,tr[i]);
close(inf);

end;
{----------------------------}
procedure heap(var a:data;n:integer;i:integer);
var
x:longint;
k:integer;
begin
x:=a[i];
k:=2*i;
while k<=n do
begin
if (k<n)and(a[k]>a[k+1]) then k:=k+1;
if x>a[k]
then begin
a[i]:=a[k];
i:=k;
k:=2*i;