binary-tree-postorder-traversal leetcode C++

Given a binary tree, return the postorder traversal of its nodes' values.

For example: Given binary tree{1,#,2,3},

1\ 2 /3

return[3,2,1].

Note: Recursive solution is trivial, could you do it iteratively?

 

C++

/** * Definition for binary tree * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: vector<int> postorderTraversal(TreeNode *root){ if (!root) return {}; vector<int> res; stack<TreeNode*> s{{root}}; while(!s.empty()){ TreeNode *t = s.top(); s.pop(); res.insert(res.begin(),t->val); if (t->left) s.push(t->left); if (t->right) s.push(t->right); } return res; } };

 

转载于:https://www.cnblogs.com/vercont/p/10210290.html