参考回答：
//深度优先搜索
//利用栈，现将右子树压栈再将左子树压栈
void DepthFirstSearch(BitNode *root){stack<BitNode*> nodeStack;nodeStack.push(root);while (!nodeStack.empty()){BitNode *node = nodeStack.top();cout << node->data << ' ';nodeStack.pop();if (node->right){nodeStack.push(node->right);}if (node->left){nodeStack.push(node->left);}}}
