大家注意!此题不可能只有81人AC的,大家肯定想复杂了,其实就是朴素算法,很容易的.
var i,j,a,b,t,s:longint;
function sum(var s:longint):longint;
var i:longint;
begin
sum:=0;
for i:=2 to trunc(sqrt(s)) do
if s mod i=0 then sum:=sum+s div i+i;
if trunc(sqrt(s))=sqrt(s) then sum:=sum-trunc(sqrt(s));
inc(sum);
end;
begin
readln(a,b);
t:=0;
for i:=a to b do
begin
s:=i;
j:=sum(s);
s:=sum(j);
if (i=s)and(i<j) then inc(t);
end;
writeln(t);
end.