UVA - 10341 - Solve It

//Root finding algorithm using newton method
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringBuffer sb = new StringBuffer();
        String m="";
        while((m=br.readLine())!=null){
            if("#".equals(m.trim()))
                break;
            StringTokenizer st=new StringTokenizer(m);
            int p=Integer.parseInt(st.nextToken()),
                    q=Integer.parseInt(st.nextToken()),
                    r=Integer.parseInt(st.nextToken()),
                    s=Integer.parseInt(st.nextToken()),
                    t=Integer.parseInt(st.nextToken()),
                    u=Integer.parseInt(st.nextToken());
            if(function(0, p, q, r, s, t, u) *function(1, p, q, r, s, t, u)>0){
               sb.append("No solution\n");
            }else{
               sb.append(String.format("%.4f\n",netwonMethod(p, q, r, s, t, u)));
            }
        }
        System.out.print(sb);
    }
    static double function(double i,int p,int q,int r,
                            int s,int t,int u){
        return 1.0*p*Math.exp(-i)+1.0*q*Math.sin(i)
                        +1.0*r*Math.cos(i)+1.0*s*Math.tan(i)+t*i*i+u;
    }
  
    static double dfunction(double i,int p,int q,int r,
                            int s,int t,int u){
        return -1.0*p*Math.exp(-i)+1.0*q*Math.cos(i)
                        -1.0*r*Math.sin(i)+1.0*s/(Math.cos(i)*Math.cos(i))+2*t*i;
    }
  
    static double netwonMethod(int p,int q,int r,
                            int s,int t,int u){
        if(function(0, p, q, r, s, t, u) ==0)
            return 0;
        double ans=0.5;
        while (true){
            double newans = ans - function(ans, p, q, r, s, t, u)/dfunction(ans, p, q, r, s, t, u);
            if (Math.abs(newans-ans) < eps)
                return ans;
            ans=newans;
        }
    }
    static double eps=1E-7;
}