jz1140【基础】亲密数对

 

//数组-轻量级函数

var
    a:array[0..200000] of longint;
    i,j,n,s:longint;
begin
    readln(n);
    for i:=2 to 2000 do
    begin
        s:=0;
        for j:=2 to i-1 do
            if i mod j=0 then inc(s,j);
        a[i]:=s;
    end;
    for i:=2 to n do
        if (a[a[i]]=i)and(a[i]<>i)and(a[i]<=n) then writeln(i,' ',a[i]);
end.