BST TREE Data Struct

#include<iostream>
using namespace std ;

struct BST{
	BST * left ;
	int data ;
	BST*right ;


};

void push () ;
void pop () ;
void search () ;
void preorder (BST*) ;
void inorder (BST *) ;
void postorder (BST *) ;

BST*root = NULL ;

int main (void){

	int pilihan ;

	while (1) {
	cout<<"Pilih Operasi Anda : "			<<endl ;
	cout<<"1. Push "						<<endl ;
	cout<<"2. Pop "							<<endl ;
	cout<<"3. Search"						<<endl ;
	cout<<"4. Traverse Preorder "			<<endl ;
	cout<<"5. Traverse Inorder "			<<endl ;
	cout<<"6. Traverse Postorder "			<<endl ;
	cout<<"7. Keluar "						<<endl ;
	cout<<"Pilihan anda : "					<<endl ;
	cin>> pilihan ;

	switch (pilihan) {
	case 1 : push () ;				break ;
	case 2 : pop () 	;			break ;
	case 3 : search () ;			break ;
	case 4 : preorder (root) ;			break ;
	case 5 : inorder (root) ;			break ;
	case 6 : postorder (root) ;			break ;

	}
	}
	system("pause") ;

	return 0 ;

}

void push (){
	BST * tmp = root ;
	BST * chelsea = new BST ;
	bool jumpa = false ;


	cout<<"mu nok wak masuk mende hux aloh : " ;
	cin>>chelsea -> data ;
	chelsea -> left = NULL ;
	chelsea -> right = NULL ;

	//true utk 1st node shj
	if(root == NULL){
		root=chelsea ;


}
//UTK 2ND NODE AND D REST
else{

	while(!jumpa){

	if (chelsea-> data <tmp -> data){
		// maka node ni anok jd anok kiri
			if(tmp -> left == NULL) {
			tmp -> left = chelsea ;
			jumpa = true ;
			}
			else
				tmp = tmp -> left ;

	}

		else if(chelsea -> data > tmp -> data){
			// maka node ni anok jd anok kanan
			if(tmp -> right == NULL) {
			tmp -> right = chelsea ;
			jumpa = true ;
			}
			else
				tmp = tmp -> right ;
		}
		else{
			//data duplicate....x leh push bewok weh
			cout<<"data duplicate...xleh push bewok weh"<<endl ;
		}
}
}
}

void pop () {

}

void search () {

}

void preorder (BST* tmp) {

	if(tmp != NULL) {
		cout<< tmp -> data ;
		preorder (tmp -> left ) ;
		preorder (tmp -> right ) ;
	}
}

void inorder (BST* tmp) {

	if(tmp != NULL) {

		inorder (tmp -> left ) ;
		cout<< tmp -> data ;
		inorder (tmp -> right ) ;
	}

}

void postorder (BST* tmp) {

	if(tmp != NULL) {

		postorder (tmp -> left ) ;
		postorder (tmp -> right ) ;
		cout<<tmp-> data ;
	}

}