Traversal of a tree in first order, middle order, and then order

The tree is traversed in order first, in order second （ Recursively defined by binary tree ）

The former sequence traversal

void PreOrder(Bitree T){
    
    if(T!=NULL){
    
        visit(T);
        PreOrder(T->Lchild);
        PreOrder(T->Rchild);
        
    }

In the sequence traversal

void PreOrder(Bitree T){
    
    if(T!=NULL){
    
        PreOrder(T->Lchild);
        visit(T);
        PreOrder(T->Rchild);
        
    }

After the sequence traversal

void PreOrder(Bitree T){
    
    if(T!=NULL){
    
        PreOrder(T->Lchild);
        PreOrder(T->Rchild);
        visit(T);
        
    }

Level traversal