Solution.java

import java.util.*;

public class Solution
{
    public int scheduleCourse(int[][] courses)
    {
        Arrays.sort(courses, new Comparator<int[]>()
        {
            @Override
            public int compare(int[] o1, int[] o2)
            {
                return o1[1] - o2[1];
            }
        });
        PriorityQueue<Integer> endDay = new PriorityQueue<Integer>(new Comparator<Integer>()
        {
            @Override
            public int compare(Integer o1, Integer o2)
            {
                return o2 - o1;
            }
        });
        int currentDay = 0;
        for (int i = 0; i < courses.length; i++)
        {
            currentDay += courses[i][0];
            endDay.add(courses[i][0]);
            if (currentDay > courses[i][1])
            {
                currentDay -= endDay.poll();
            }
        }
        return endDay.size();
    }
}