题解 | #二叉树的后序遍历#

class Solution {
public:
    vector<int> postorderTraversal(TreeNode* root) {
        vector<int> v;
        stack<TreeNode*> s;
        TreeNode* h = root;
        TreeNode* cur = root;
        if(!root) return v;
        s.push(root);
        while(!s.empty())
        {
            TreeNode* temp = s.top();
            if(temp->left && h!=temp->left && h!=temp->right){
                s.push(temp->left);
            }else if(temp->right && h!=temp->right){
                s.push(temp->right);
            }else{
                v.push_back(temp->val);
                s.pop();
                h = temp;
            }
        }
        return v;
    }
};