RosettaCodeData/Task/Pernicious-numbers/Ada/pernicious-numbers-1.ada
2015-02-20 09:02:09 -05:00

40 lines
1 KiB
Ada

with Ada.Text_IO, Population_Count; use Population_Count;
procedure Pernicious is
Prime: array(0 .. 64) of Boolean;
-- we are using 64-bit numbers, so the population count is between 0 and 64
X: Num; use type Num;
Cnt: Positive;
begin
-- initialize array Prime; Prime(I) must be true if and only if I is a prime
Prime := (0 => False, 1 => False, others => True);
for I in 2 .. 8 loop
if Prime(I) then
Cnt := I + I;
while Cnt <= 64 loop
Prime(Cnt) := False;
Cnt := Cnt + I;
end loop;
end if;
end loop;
-- print first 25 pernicious numbers
X := 1;
for I in 1 .. 25 loop
while not Prime(Pop_Count(X)) loop
X := X + 1;
end loop;
Ada.Text_IO.Put(Num'Image(X));
X := X + 1;
end loop;
Ada.Text_IO.New_Line;
-- print pernicious numbers between 888_888_877 and 888_888_888 (inclusive)
for Y in Num(888_888_877) .. 888_888_888 loop
if Prime(Pop_Count(Y)) then
Ada.Text_IO.Put(Num'Image(Y));
end if;
end loop;
Ada.Text_IO.New_Line;
end;