630

class Solution {
public:
    int scheduleCourse(vector<vector<int>>& courses) {
        sort(courses.begin(), courses.end(), [](const vector<int> &a, vector<int> &b){return a[1] < b[1];});
        priority_queue<int> pq;

        int totalTime = 0;
        for(auto c: courses){
            if(totalTime + c[0] <= c[1]){
                totalTime += c[0];
                pq.push(c[0]);
            }
            else{
                if(!pq.empty() && pq.top() > c[0]){
                    int lastTime = pq.top();
                    pq.pop();
                    totalTime += (c[0]-lastTime);
                    pq.push(c[0]);
                }
            }
        }

        return pq.size();
    }
};