45 lines
1.4 KiB
C++
45 lines
1.4 KiB
C++
#include <iostream>
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/**
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* Definition for a binary tree node.
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*/
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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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TreeNode() : val(0), left(nullptr), right(nullptr) {}
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TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
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TreeNode(int x, TreeNode* left, TreeNode* right) : val(x), left(left), right(right) {}
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~TreeNode() { delete this->left; delete this->right; }
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};
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class Solution {
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private:
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static int dfs(const TreeNode* const node, int L, int R) {
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int LDist = (L - node->val) >= 0 ? (L - node->val) : (node->val - L);
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int RDist = (R - node->val) >= 0 ? (R - node->val) : (node->val - R);
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int mid, ret = LDist > RDist ? LDist : RDist;
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int nL = L < node->val ? L : node->val, nR = R > node->val ? R : node->val;
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if (node->left) {
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mid = dfs(node->left, nL, nR);
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ret = ret > mid ? ret : mid;
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}
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if (node->right) {
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mid = dfs(node->right, nL, nR);
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ret = ret > mid ? ret : mid;
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}
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return ret;
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}
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public:
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static int maxAncestorDiff(const TreeNode* const root) {
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return dfs(root, root->val, root->val);
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}
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};
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int main() {
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// TreeNode root(1, nullptr, new TreeNode(2, nullptr, new TreeNode(0, new TreeNode(3), nullptr)));
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TreeNode root(8, new TreeNode(3, new TreeNode(1), new TreeNode(6, new TreeNode(4), new TreeNode(7))), new TreeNode(10, nullptr, new TreeNode(14, new TreeNode(13), nullptr)));
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std::printf("%d\n", Solution::maxAncestorDiff(&root));
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return 0;
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}
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