解法

class Solution {
    public int findMinArrowShots(int[][] points) {
        // 按气球起始边界从左往右排序
        Arrays.sort(points, Comparator.comparingInt(o -> o[0]));
        int result = 1;
        int minRight = points[0][1];
        for (int i = 1; i < points.length; i++) {
            // 左边界大于最小公共右边界，需要的箭加1
            if (points[i][0] > minRight) {
                result++;
                minRight = points[i][1];
            } else {
                // 重合继续求最小右边界
                minRight = Math.min(minRight, points[i][1]);
            }
        }
        return result;
    }
}