1964

class Solution {
public:
    vector<int> longestObstacleCourseAtEachPosition(vector<int>& obs) {
        vector<int> seq;
        vector<int> ans;
        for(auto num: obs){
            auto it = upper_bound(seq.begin(), seq.end(), num)-seq.begin();
            if(it == seq.size()){
                seq.push_back(num);
                ans.push_back(seq.size());
                continue;
            }
            seq[it] = num;
            ans.push_back(it+1);
        }
        return ans;
    }
};