blob: 3f6917787b3094e21a31038e2e0081d78111061d (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
// 662. Maximum Width of Binary Tree
#include "leetcode.h"
/*
* given 'root' of binary tree, return the maximum width of the
* given tree. the maximum width of a tree is the maximum width
* among all levels. 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.
*/
class Solution {
public:
int widthOfBinaryTree(TreeNode *root) {
if (root == NULL)
return 0;
int max_width = 1;
queue<pair<TreeNode *, int>> qp;
qp.push({root, 0});
while (!qp.empty()) {
int level_size = qp.size();
int start_idx = qp.front().second;
int end_idx = qp.back().second;
max_width = max(max_width, end_idx - start_idx + 1);
for (int i = 0; i < level_size; ++i) {
auto node_idx_pair = qp.front();
TreeNode *node = node_idx_pair.first;
int node_idx = node_idx_pair.second - start_idx;
qp.pop();
if (node->left != nullptr)
qp.push({node->left, 2LL * node_idx + 1});
if (node->right != nullptr)
qp.push({node->right, 2LL * node_idx + 2});
}
}
return max_width;
}
};
|