https://leetcode.com/problems/minimum-number-of-arrows-to-burst-balloons/

与会议室排期问题，很相似。

package com.company;import java.util.*;class Balloon {    int[] points;    boolean check;    Balloon(int s, int e) {        points = new int[2];        points[0] = s;        points[1] = e;        check = false;    }}class MyComparator implements Comparator
     
       {    int index;    MyComparator(int i) {        index = i;    }    @Override    public int compare(Balloon o1, Balloon o2) {        return o1.points[index] - o2.points[index];    }}class Solution {    public int findMinArrowShots(int[][] points) {        List
      
        endList = new ArrayList<>();        List
       
         startList = new ArrayList<>();        for (int i=0; i
        
          iter = endList.iterator();        while (iter.hasNext()) {            Balloon tmp = iter.next();            if (tmp.check) {                continue;            }            ret++;            while (index < points.length && startList.get(index).points[0] <= tmp.points[1]) {                startList.get(index).check = true;                index++;            }        }        return ret;    }}public class Main {    public static void main(String[] args) throws InterruptedException {        System.out.println("Hello!");        Solution solution = new Solution();        // Your Codec object will be instantiated and called as such:        int[][] points = {
   {10,16}, {2,8}, {1,6}, {7,12}};        int ret = solution.findMinArrowShots(points);        System.out.printf("ret:%d\n", ret);        System.out.println();    }}