How to find the minimal element of a BST?

Question

I'm a beginner to c++ and am having problems with finding the minimal element of a BST. The BST is implemented in this way:

class Tree{
struct Node {
int Element;
Node *Left, *Right;
Node(int Element) : Element(Element), Left(0), Right(0){}
};

Node *Root;
void InOrder(void(*Action)(int&), Node *Current);
void Destroy(Node *Current);

public:

Tree() : Root(0){}
void Insert(int Element);
void InOrder(void(*Action)(int&)) {InOrder(Action,Root);}
void Destroy() {Destroy(Root);}
};

The InOrder, Destroy and Insert methods are implemented like this:

void Tree::Insert(int Element) {
Node *NewElement = new Node(Element);
if(!Root) Root = NewElement;

 else {
 Node *Previous, *Current = Root;

  while(Current) {
   Previous = Current;
   if(Element < Current->Element) Current = Current->Left;
   else Current = Current->Right;
  }

 if(Element < Previous->Element) Previous->Left = NewElement;
 else Previous->Right = NewElement;
 }
}

void Tree::InOrder(void(*Action)(int&),Node *Current) {
  if(Current) {
  InOrder(Action,Current->Left);
  Action(Current->Element);
  InOrder(Action,Current->Right);
}

}

void Tree::Destroy(Node *Current) {
 if(Current) {
  Destroy(Current->Left);
  Destroy(Current->Right);
  delete Current;
 }
}

And the main function and function which I use to print the numbers look like this:

void Print(int &e) {
 cout << e << endl;
}

int main() {
 Tree t;
 while(1) {
 int Number;
 cout << "Insert number (insert 0 to end): ";
 cin >> Number;
 if(Number == 0) break;
 t.Insert(Number);
 }

 t.InOrder(Print);
 t.Destroy();
 getch();
}

As you may noticed, the InOrder method is implemented also, maybe it can be used in some way to help solve my problem... Sorry for my bad English :/

Answer 1

The minimal value would be the first value that calls Action in the above code. Go left as far as you can, and the minimal value you shall find...