public class Main {
    public static void main(String[] args) {
        double bulletSpeed = 900; // 900m/s为M416步枪子弹速度
        double targetSpeed = 50; // 假设目标速度为50m/s
        double distance = 1000; // 假设目标与射手之间的距离为1000m

        double angle = calculateBulletRange(bulletSpeed, targetSpeed, distance);
        System.out.println("子弹飞行角度：" + angle);
    }

    public static double calculateBulletRange(double bulletSpeed, double targetSpeed, double distance) {
        // 计算公式：角度 = atan(距离 / (子弹速度 - 目标速度))
        double angle = Math.atan(distance / (bulletSpeed - targetSpeed));
        return angle;
    }
}