54 lines
1.6 KiB
C++
54 lines
1.6 KiB
C++
#include <algorithm>
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#include <queue>
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#include <tuple>
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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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* 662. Maximum Width of Binary Tree
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*
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* Given the root of a binary tree, return the maximum width of the given tree.
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* The maximum width of a tree is the maximum width among all levels.
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* The width of one level is defined as the length between the end-nodes (the leftmost and rightmost non-null nodes), where the null nodes between the end-nodes that would be present in a complete binary tree extending down to that level are also counted into the length calculation.
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* It is guaranteed that the answer will in the range of a 32-bit signed integer.
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*/
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class Solution {
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public:
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static int widthOfBinaryTree(const TreeNode* root);
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};
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int Solution::widthOfBinaryTree(const TreeNode* root) {
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std::queue<std::tuple<const TreeNode*, int, unsigned long long>> q;
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q.emplace(root, 0, 1);
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int curLevel = -1;
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std::pair<unsigned long long, unsigned long long> ans = {0, 0};
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unsigned long long ret = 1;
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while (!q.empty()) {
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auto [node, level, id] = q.front();
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q.pop();
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if (curLevel != level) {
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curLevel = level;
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ret = std::max(ans.second - ans.first + 1, ret);
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ans = {id, id};
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}
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ans.first = std::min(id, ans.first);
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ans.second = std::max(id, ans.second);
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if (node->left)
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q.emplace(node->left, 1 + level, id << 1);
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if (node->right)
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q.emplace(node->right, 1 + level, 1 | (id << 1));
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}
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return std::max(ret, ans.second - ans.first + 1);
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}
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int main() {
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;
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}
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