import java.lang.*;
import java.io.*;
import java.util.*;

//Machine Learning by function approximation for tank(moving target) bombardment
//assume distance=A*angle*speed*speed

//Stdout for turns to hit, final constant A
//Stderr for A, Angle, Speed, Distance, Target for each bombing
//java Tank4 > tank4out.csv 2> tank4err.csv

public class Tank4 {

    public static void main(String[] args){

	Random rand = new Random(0); //set random seed

	//max_range = 1000; max_angle = Math.PI/2; max_speed = 100;
	//assume d = A*angle*speed*speed
	//assume fixed angle(=0.8)
	//therefore speed = Sqrt(d / (A * angle))
        double A=rand.nextDouble()*10; //initialize A

	System.out.println("Turns, A");

	for(int loop=0; loop<100; loop++){ //loop 100 times
	    int counter = 0;             //Initialize counter

	    System.err.println("A, Angle, Speed, Distance, Target");

	    while(true){ //Loop until hit
		counter++;

		double angle;
		double speed;
		double distance;
		int target = (int)((rand.nextDouble()*1000.0)+1.0); //move target tank
		//assume d=A*angle*speed*speed
		//assume fixed angle(=0.8)
		//therefore speed = Sqrt(d / (A * angle))
		angle = 0.8;
		speed = Math.sqrt(target / ( A * angle ));
		distance = (speed * speed * Math.sin( angle * 2.0 ))/9.8 ;
		    
		//output shot result
		System.err.println(A+"A, "+angle+", "+speed+", "+distance+", "+target);
		
		if(distance > (target-10) && distance < (target+10)) break; //if hit then exit while
		
		//if overshot
		if(distance > target){
		    A = A*1.1; //10% more
		}else{
		    A = A*0.9; //10% less
		}

	    }//end while(true)

	    System.err.println("---HIT!!!---");
	    System.out.println(counter+", "+A);

	}//end for(loop)



    }//end main()

}//end class Tank4