1964. 找出到每个位置为止最长的有效障碍赛跑路线

C++代码 upper_bound

class Solution {
public:
    vector<int> longestObstacleCourseAtEachPosition(vector<int>& obstacles) {
        vector<int> ans,d;

        for (int i = 0; i < obstacles.size(); ++i) {

            int k = upper_bound(d.begin(), d.end(), obstacles[i]) - d.begin();

            if (k == d.size()) {
                d.push_back(obstacles[i]);
            } else {
                d[k] = obstacles[i];
            }
            ans.push_back(k + 1);
        }

        return ans;
    }
};