求鉴定，这排序是否稳定

var
n,i,j,min,t,tt:longint;
a:array[1..1000]of longint;
begin
readln(n);
for i:=1 to n do
read(a[i]);
readln;
for i:=1 to n do
begin
min:=maxlongint;
for j:=i to n do
if a[j]<min then
begin
min:=a[j];
tt:=j;
end;
t:=a[i];
a[i]:=a[tt];
a[tt]:=t;
end;
for i:=1 to n-1 do
write(a[i],' ');
writeln(a[n]);
end.
我知道这是选择排序，但我觉得它是稳定的