50 lines
1.3 KiB
C++
50 lines
1.3 KiB
C++
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#include <unordered_map>
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#ifdef _MF_TEST
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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)
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: val(x), left(left), right(right) {}
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};
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#endif
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class Solution {
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auto isEvenOddTree(std::unordered_map<int, int> &view, int level,
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TreeNode *root) const -> bool {
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if (root == nullptr) {
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return true;
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}
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// check the parity
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if (level % 2 == root->val % 2) {
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return false;
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}
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// check the ordering
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auto &last = view[level];
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if (last != 0 && level % 2 == 0 && root->val <= last) {
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return false;
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} else if (last != 0 && level % 2 != 0 && root->val >= last) {
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return false;
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}
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last = root->val;
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if (!isEvenOddTree(view, level + 1, root->left) ||
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!isEvenOddTree(view, level + 1, root->right)) {
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return false;
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}
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return true;
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}
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public:
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bool isEvenOddTree(TreeNode *root) const {
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std::unordered_map<int, int> leftview;
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return isEvenOddTree(leftview, 0, root);
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}
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};
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