템플릿으로 바꾸기..ㅠ

#include <iostream>
using namespace std;
class Tree;
class TreeNode;
class Pair{
	friend class Tree;
	private:
		int first;
		char element;
	public:
		Pair(){
			first = '\0';
			element = '\0';
		}
		Pair(int f, char e){
			first = f;
			element = e;
		}
};
class TreeNode{
	friend class Tree;
	private:
		Pair data;
		TreeNode *leftChild;
		TreeNode *rightChild;
	public:
		TreeNode(){
			leftChild = NULL;
			rightChild = NULL;
		}
		TreeNode(Pair da){
			data = da;
		}
		void setL(TreeNode* L){
			leftChild = L;
		}
		void setR(TreeNode* R){
			rightChild = R;
		}
};
class Tree{
	public:
 
	private:
		TreeNode *root;
};
int main(){
	return 0;
}