Initial data commit

Task/Totient-function/Pascal/totient-function-1.pas

@@ -0,0 +1,65 @@
+{$IFDEF FPC}
+  {$MODE DELPHI}
+{$IFEND}
+function gcd_mod(u, v: NativeUint): NativeUint;inline;
+//prerequisites  u > v and u,v > 0
+  var
+    t: NativeUInt;
+  begin
+    repeat
+      t := u;
+      u := v;
+      v := t mod v;
+    until v = 0;
+    gcd_mod := u;
+  end;
+
+function Totient(n:NativeUint):NativeUint;
+var
+  i : NativeUint;
+Begin
+  result := 1;
+  For i := 2 to n do
+    inc(result,ORD(GCD_mod(n,i)=1));
+end;
+
+function CheckPrimeTotient(n:NativeUint):Boolean;inline;
+begin
+  result :=  (Totient(n) = (n-1));
+end;
+
+procedure OutCountPrimes(n:NativeUInt);
+var
+  i,cnt :  NativeUint;
+begin
+  cnt := 0;
+  For i := 1 to n do
+    inc(cnt,Ord(CheckPrimeTotient(i)));
+  writeln(n:10,cnt:8);
+end;
+
+procedure display(n:NativeUint);
+var
+  idx,phi : NativeUint;
+Begin
+  if n = 0 then
+    EXIT;
+  writeln('number n':5,'Totient(n)':11,'isprime':8);
+  For idx := 1 to n do
+  Begin
+    phi := Totient(idx);
+    writeln(idx:4,phi:10,(phi=(idx-1)):12);
+  end
+end;
+var
+  i : NativeUint;
+Begin
+  display(25);
+
+  writeln('Limit  primecount');
+  i := 100;
+  repeat
+    OutCountPrimes(i);
+    i := i*10;
+  until i >100000;
+end.