int max_path_sum(TreeNode *root, int &max_sum){
if(root == NULL) return 0;
int left = max_path_sum(root->left, max_sum);
int right = max_path_sum(root->right, max_sum);
if(left < 0) left = 0;
if(right < 0) right = 0;
if(left + right + root->val > max_sum) max_sum = left + right + root->val;
if(left > right) return left + root->val;
else return right + root->val;
}
void max_path_sum(TreeNode *node, int &tmp_sum, int &max_sum) {
if (node == NULL) {
tmp_sum = 0;
return ;
}
int left_sum = 0;
int right_sum = 0;
max_path_sum(node->left, left_sum, max_sum);
max_path_sum(node->right, right_sum, max_sum);
tmp_sum = max(node->val, max(node->val + left_sum, node->val + right_sum));
max_sum = max(max_sum, max(tmp_sum, node->val + left_sum + right_sum));
}
int main(int argc, char const* argv[])
{
node *tree = prepare_tree();
printf("max path sum = %d\n",max_path_sum(tree));
printf("expected value = 20\n");
return 0;
}
int maxPathSum(TreeNode *root) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
int max_sum = INT_MIN;
max_path_sum(root, max_sum);
return max_sum;
}
int maxPathSum(TreeNode *root) {
int max_sum = INT_MIN;
int tmp_sum;
max_path_sum(root, tmp_sum, max_sum);
return max_sum;
}
