Given a binary tree, return the postorder traversal of its nodes' values.
Example:
Input: [1,null,2,3] 1 \ 2 / 3 Output: [3,2,1]Follow up: Recursive solution is trivial, could you do it iteratively?
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和leetcode 144. Binary Tree Preorder Traversal类似。
emmm，这个题是hard难度题，大概是在迭代上是不好写吧，不过递归是很容易写的。
C++代码：
/** * Definition for a binary tree node. * 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) { vector<int> vec; postorder(root,vec); return vec; } void postorder(TreeNode *root,vector<int> &vec){ if(!root) return; postorder(root->left,vec); postorder(root->right,vec); vec.push_back(root->val); } };
转载于:https://www.cnblogs.com/Weixu-Liu/p/10773753.html
