Binary Tree Pruning(C++二叉树剪枝)
解题思路:
(1)后序遍历
(2)和Delete Leaves With a Given Value题目类似
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode() : val(0), left(nullptr), right(nullptr) {}
* TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
* TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
public:
TreeNode* pruneTree(TreeNode* root) {
if(root==NULL) return NULL;
root->left=pruneTree(root->left);
root->right=pruneTree(root->right);
if(root->val==0 && !root->left && !root->right) root=NULL;
return root;
}
};
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