452. 用最少数量的箭引爆气球

class Solution {
    public int findMinArrowShots(int[][] points) {
        if(points.length == 0) return 0;
        Arrays.sort(points, (p1, p2) -> p1[1] < p2[1] ? -1 : 1);
        int res = 1;
        int pre = points[0][1];
        for (int i = 1; i < points.length; i++) {
            if (points[i][0] > pre) {
                res++;
                pre = points[i][1];
            }
        }
        return res;

    }
}