Leetcode-Daily/Jan_7(1339) at main · dakshitcodes/Leetcode-Daily · GitHub

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
41
42
43
44
45
/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode() : val(0), left(nullptr), right(nullptr) {}
 *     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
 *     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
 * };
 */
class Solution {
public:
    long long MOD = 1e9 + 7;
    long long ans = 0;

    long long dfs(TreeNode* node) {
        if (!node) return 0;

        node->val += dfs(node->left) + dfs(node->right);
        return node->val;
    }

    int maxProduct(TreeNode* root) {
        long long total = dfs(root);

        queue<TreeNode*> q;
        q.push(root);

        while (!q.empty()) {
            TreeNode* node = q.front();
            q.pop();

            if (!node) continue;

            long long cur = (total - node->val) * node->val;
            ans = max(ans, cur);

            if (node->left) q.push(node->left);
            if (node->right) q.push(node->right);
        }

        return ans % MOD;
    }
};