Binary Tree Maximum Path Sum

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
private:
    int findMaxPathSum(TreeNode* root, int* result) {
        if (root == NULL)
        {
            return INT16_MIN;
        }
        if (root->left == NULL && root->right == NULL) {
            *result = max(*result, root->val);
            return root->val;
        }

        int leftMaxPathSum = findMaxPathSum(root->left, result);
        int rightMaxPathSum = findMaxPathSum(root->right, result);
        int curMaxPathSum = max({ root->val, leftMaxPathSum + root->val, rightMaxPathSum + root->val });

        *result = max({ *result, curMaxPathSum, leftMaxPathSum + rightMaxPathSum + root->val });
        return curMaxPathSum;
    }

public:
    int maxPathSum(TreeNode* root) {
        int result = INT16_MIN;
        findMaxPathSum(root, &result);

        return result;
    }
};