Leetcode#94 Binary Tree Inorder Traversal

原题地址

考察非递归写法。前序遍历可以参考这篇文章，后序遍历可以参考这篇

代码：

vector<int> inorderTraversal(TreeNode *root) {
        TreeNode *node = NULL;
        stack<TreeNode *> st;
        vector<int> path;
        
        node = root;
        while (node) {
            while (node) {
                st.push(node);
                node = node->left;
            }
            node = NULL;
            while (!st.empty() && !node) {
                path.push_back(st.top()->val);
                node = st.top()->right;
                st.pop();
            }
        }
        
        return path;
}