voidLevelOrder(BiTree *root){
if(root ==NULL)return;
queue<binode*> Q;
Q.push(root);//while there is at least one discovered nodewhile(!Q.empty()){
BiTree * current = Q.front();
Q.pop();// removing the element at front
cout<<current->data<<" ";if(current->lchild !=NULL) Q.push(current->lchild);if(current->rchild !=NULL) Q.push(current->rchild);}}