30 lines
1.1 KiB
C++
30 lines
1.1 KiB
C++
#include <iostream>
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struct TreeNode {
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int val;
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TreeNode* left;
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TreeNode* right;
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explicit TreeNode(int x, TreeNode* left = nullptr, TreeNode* right = nullptr) : val(x), left(left), right(right) {}
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};
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/**
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* 669. Trim a Binary Search Tree
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* Given the root of a binary search tree and the lowest and highest boundaries as low and high, trim the tree so that all its elements lies in [low, high]. Trimming the tree should not change the relative structure of the elements that will remain in the tree (i.e., any node's descendant should remain a descendant). It can be proven that there is a unique answer.
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* Return the root of the trimmed binary search tree. Note that the root may change depending on the given bounds.
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*/
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class Solution {
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public:
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static TreeNode* trimBST(TreeNode* root, int low, int high) {
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if (!root)
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return nullptr;
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if (root->val < low)
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return trimBST(root->right, low, high);
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if (high < root->val)
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return trimBST(root->left, low, high);
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root->left = trimBST(root->left, low, high);
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root->right = trimBST(root->right, low, high);
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return root;
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}
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};
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