"0.5;3;1.5-0.3;1.4;3.1"

import java.io.*;
import java.net.*;

class Client{
	public static void main(String argv[]) throws Exception {
		double prodScal;
		String numElem;
		
		BufferedReader inFromUser1 = new BufferedReader(new InputStreamReader((System.in)));
		BufferedReader inElem = new BufferedReader(new InputStreamReader((System.in)));
		BufferedReader inFromUser2 = new BufferedReader(new InputStreamReader((System.in)));
		
		Socket clientSocket = new Socket("localhost", 6789);
		
		DataOutputStream outToServer1= new DataOutputStream(clientSocket.getOutputStream());
		DataOutputStream outToServer2 = new DataOutputStream(clientSocket.getOutputStream());
		DataOutputStream outToServer3 = new DataOutputStream(clientSocket.getOutputStream());
		
		BufferedReader inFromServer = new BufferedReader( new InputStreamReader(clientSocket.getInputStream()));
		
		System.out.println("Quanti elementi deve avere ciascuno dei due array?");
		numElem=inElem.readLine();
		outToServer1.writeBytes(numElem);
		
		//inserire gli elementi dell'array uno da tastiera
		for(int i=0; i<Integer.parseInt(numElem); i++){
			System.out.println("Inserire l'elemento n. "+ i+" dell'array 1 (numero elementi= "+numElem +" ):");
			String elemento=inFromUser1.readLine();
			outToServer2.writeBytes(elemento);
		}
		
		//inserire gli elementi dell'array 2 da tastiera
		for(int j=0; j<Integer.parseInt(numElem); j++){
			System.out.println("Inserire l'elemento n. "+ j+" dell'array 2 :");
			String elemento2=inFromUser2.readLine();
			outToServer3.writeBytes(elemento2);
		}
		
		
		prodScal = Double.parseDouble(inFromServer.readLine());
		
		System.out.println("FROM SERVER : Il prodotto vettoriale è " + prodScal);
		
		clientSocket.close();
															}
				}

import java.io.*;
import java.net.*;

class Server{
	public static void main(String argv[]) throws Exception {
		
		double[] primoArray = null;
		double[] secondoArray = null;
		String numElem;
		double prodScal = 0;
		
		ServerSocket welcomeSocket = new ServerSocket(6789);
		
			while(true) {
				
					Socket connectionSocket = welcomeSocket.accept();
					
					System.out.println("server connesso");
					
					BufferedReader inFromClient1 = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
					BufferedReader inFromClient3 = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
					BufferedReader inFromClient2 = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
					
					DataOutputStream outToClient = new DataOutputStream(connectionSocket.getOutputStream());
					
					numElem=inFromClient3.readLine();
					
					//creo array con elem in arrivo dal client
					for(int i=0; i<Integer.parseInt(numElem); i++){
						primoArray[i]=Double.parseDouble(inFromClient1.readLine());
					} 
					
					//creo array con elem in arrivo dal client
					for(int j=0; j<Integer.parseInt(numElem); j++){
						secondoArray[j]=Double.parseDouble(inFromClient2.readLine());
					}
					
					
					//calcolo prodVett
					for(int i=0; i<primoArray.length; i++){
							
						prodScal += primoArray[i]*secondoArray[i];
					}
					
					System.out.println("il prod scal è:"+ prodScal);
					
					outToClient.writeDouble(prodScal);
					
						}
															}
				}