1 files changed, 72 insertions, 0 deletions
diff --git a/packages/fcl-stl/src/ghashset.pp b/packages/fcl-stl/src/ghashset.pp
new file mode 100644
index 0000000000..ad45dce165
--- /dev/null
+++ b/packages/fcl-stl/src/ghashset.pp
@@ -0,0 +1,72 @@
+{$mode objfpc}
+
+{unit ghashset;
+
+interface}
+uses gvector;
+
+const baseSize = 8;
+
+
+
+{Thash should have one class function hash(a:T, n:longint):longint which return uniformly distributed
+value in range <0,n-1> base only on arguments}
+
+type 
+  generic hashset<T, Thash>=class
+    private type TContainer = specialize vector<T>;
+    type TTable = specialize vector<TContainer>;
+    var data:TTable;
+    public constructor create;
+    procedure insert(value:T);inline;
+    function find(value:T):boolean;inline;
+  end;
+
+{implementation}
+
+constructor hashset.create;
+var i:longint;
+begin
+  data:=TTable.create;
+  data.resize(8);
+  for i:=0 to 7 do
+    data[i]:=TContainer.create;
+end;
+
+function hashset.find(value:T):boolean;inline;
+var i,h,bs:longint;
+begin
+  h:=Thash.hash(value,data.size);
+  bs:=data.getValue(h).size;
+  for i:=0 to bs-1 do begin
+    if (data.getvalue(h).getvalue(i)=value) then exit(true);
+  end;
+  exit(false);
+end;
+
+procedure hashset.insert(value:T);inline;
+begin
+  if (find(value)) then exit;
+  (data[Thash.hash(value,data.size)]).pushback(value);
+end;
+
+type hint=class
+  class function hash(a,n:longint):longint;
+end;
+
+class function hint.hash(a,n:longint):longint;
+begin
+  hash:= a mod n;
+end;
+
+type hsli = specialize hashset<longint, hint>;
+
+var data:hsli; i,n:longint;
+
+begin
+  data:=hsli.create;
+  for i:=0 to 10 do
+    data.insert(i);
+  for i:=0 to 13 do
+    writeln(data.find(i));
+end.