Data commit

Task/Happy-numbers/Delphi/happy-numbers.delphi

@@ -0,0 +1,64 @@
+program Happy_numbers;
+
+{$APPTYPE CONSOLE}
+
+uses
+  System.SysUtils,
+  Boost.Int;
+
+type
+  TIntegerDynArray = TArray<Integer>;
+
+  TIntHelper = record helper for Integer
+    function IsHappy: Boolean;
+    procedure Next;
+  end;
+
+{ TIntHelper }
+
+function TIntHelper.IsHappy: Boolean;
+var
+  cache: TIntegerDynArray;
+  sum, n: integer;
+begin
+  n := self;
+  repeat
+    sum := 0;
+    while n > 0 do
+    begin
+      sum := sum + (n mod 10) * (n mod 10);
+      n := n div 10;
+    end;
+    if sum = 1 then
+      exit(True);
+
+    if cache.Has(sum) then
+      exit(False);
+    n := sum;
+    cache.Add(sum);
+  until false;
+end;
+
+procedure TIntHelper.Next;
+begin
+  inc(self);
+end;
+
+var
+  count, n: integer;
+
+begin
+  n := 1;
+  count := 0;
+  while count < 8 do
+  begin
+    if n.IsHappy then
+    begin
+      count.Next;
+      write(n, ' ');
+    end;
+    n.Next;
+  end;
+  writeln;
+  readln;
+end.