树 前序中序后序 递归 遍历

class Node{
public:
int data;
Node *pLeft = NULL;
Node *pRight = NULL;
};

void qianxubianli(Node *pRoot){

if (pRoot == NULL){
return;
}
cout << pRoot->data << " ";
qianxubianli( pRoot->pLeft);
qianxubianli( pRoot->pRight);

}


void zhongxubianli(Node *pRoot){
if (pRoot == NULL){
return;
}
zhongxubianli(pRoot->pLeft);
cout << pRoot->data << " ";
zhongxubianli(pRoot->pRight);

}


void houxubianli(Node *pRoot){
if (pRoot == NULL){
return;
}
houxubianli(pRoot->pLeft);
houxubianli(pRoot->pRight);
   cout << pRoot->data << " ";
}