class Solution {
public:
int base, count, maxCount;
vector<int> answer;
void update(int x) {
if (x == base) {
++count;
} else {
count = 1;
base = x;
}
if (count == maxCount) {
answer.push_back(base);
}
if (count > maxCount) {
maxCount = count;
answer = vector<int> {
base};
}
}
vector<int> findMode(TreeNode* root) {
TreeNode *cur = root, *pre = nullptr;
while (cur) {
if (!cur->left) {
update(cur->val);
cur = cur->right;
continue;
}
pre = cur->left;
while (pre->right && pre->right != cur) {
pre = pre->right;
}
if (!pre->right) {
pre->right = cur;
cur = cur->left;
} else {
pre->right = nullptr;
update(cur->val);
cur = cur->right;
}
}
return answer;
}
};