Initial data commit

Task/Totient-function/Ada/totient-function.ada

@@ -0,0 +1,72 @@
+with Ada.Text_IO;
+with Ada.Integer_Text_IO;
+
+procedure Totient is
+
+   function Totient (N : in Integer) return Integer is
+      Tot : Integer := N;
+      I   : Integer;
+      N2  : Integer := N;
+   begin
+      I := 2;
+      while I * I <= N2 loop
+         if N2 mod I = 0 then
+            while N2 mod I = 0 loop
+               N2 := N2 / I;
+            end loop;
+            Tot := Tot - Tot / I;
+         end if;
+
+         if I = 2 then
+            I := 1;
+         end if;
+         I := I + 2;
+      end loop;
+
+      if N2 > 1 then
+         Tot := Tot - Tot / N2;
+      end if;
+
+      return Tot;
+   end Totient;
+
+   Count : Integer := 0;
+   Tot   : Integer;
+   Placeholder : String := "  n  Phi  Is_Prime";
+   Image_N     : String renames Placeholder ( 1 ..  3);
+   Image_Phi   : String renames Placeholder ( 6 ..  8);
+   Image_Prime : String renames Placeholder (11 .. 17);
+   use Ada.Text_IO;
+   use Ada.Integer_Text_IO;
+begin
+
+   Put_Line (Placeholder);
+
+   for N in 1 .. 25 loop
+      Tot := Totient (N);
+
+      if N - 1 = Tot then
+         Count := Count + 1;
+      end if;
+      Put (Image_N, N);
+      Put (Image_Phi, Tot);
+      Image_Prime := (if N - 1 = Tot then "    True" else "   False");
+      Put_Line (Placeholder);
+   end loop;
+   New_Line;
+
+   Put_Line ("Number of primes up to " & Integer'(25)'Image &" =" & Count'Image);
+
+   for N in 26 .. 100_000 loop
+      Tot := Totient (N);
+
+      if Tot = N - 1 then
+         Count := Count + 1;
+      end if;
+
+      if N = 100 or N = 1_000 or N mod 10_000 = 0 then
+         Put_Line ("Number of primes up to " & N'Image & " =" & Count'Image);
+      end if;
+   end loop;
+
+end Totient;