import java.io.FileInputStream;  ex3
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Scanner;

public class Ex3
{
	static ArrayList<String> PeopleOver18()
	{
		ArrayList<String> list = new ArrayList<String>();
		FileInputStream f = null;
		try
		{
			f = new FileInputStream("clients.txt");
			Scanner s = new Scanner(f);

			while(s.hasNext())
			{
				String nume = s.next();
				String prenume = s.next();
				int varsta = s.nextInt();

				if(varsta>=18)
					list.add(prenume+" "+nume);
			}

		}
		catch (FileNotFoundException e)
		{
			System.out.println("Cannot find file! \n"+e.getMessage());
		}
		finally
		{
			try {
				f.close();
			}
			catch (IOException e)
			{
				System.out.println("File not found");
				e.printStackTrace();
			}
		}
		return list;
	}

	static ArrayList<String> PeopleUnder18()
	{
		ArrayList<String> list = new ArrayList<String>();
		FileInputStream f = null;

		try
		{
			f = new FileInputStream("clients.txt");
			Scanner s = new Scanner(f);

			while(s.hasNext())
			{
				String nume = s.next();
				String prenume = s.next();
				int varsta = s.nextInt();

				if(varsta<18)
					list.add(prenume+" "+nume);
			}

		}
		catch (FileNotFoundException e)
		{
			System.out.println("Cannot find file! \n"+e.getMessage());
		}
		finally
		{
			try {
				f.close();
			}
			catch (IOException e)
			{
				System.out.println("File not found");
				e.printStackTrace();
			}
		}
		return list;

	}

	public static void main(String[] args)
	{
		System.out.println("Numar persoane majore: "+PeopleOver18().size());
		System.out.println(PeopleOver18());
		System.out.println("Numar persoane minore: "+PeopleUnder18().size());
		System.out.println(PeopleUnder18());
	}
}

import java.io.BufferedReader;  ex2
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;

public class Ex2
{
	public static boolean FindUser(String user)
	{
		boolean found = false;

		try
		{
			FileInputStream f = new FileInputStream("users.txt");
			Scanner s = new Scanner(f);
			String aux ="";
			while(s.hasNext() && found == false)
			{
				aux = s.next();
				if(user.compareTo(aux)==0)
					found = true;
				s.next();
			}
		}
		catch (FileNotFoundException e)
		{
			System.out.println(e.getMessage());

		}

		return found;
	}

	static boolean ValidateLogin(String user,String pass)
	{
		boolean found = false;
		FileInputStream f = null;
		try
		{
			 f = new FileInputStream("users.txt");
			Scanner s = new Scanner(f);
			String aux ="";
			String loginString = user+" "+pass;
			while(s.hasNext() && found == false)
			{
				aux = s.nextLine();
				if(aux.compareTo(loginString)==0)
					found = true;
			}
		}
		catch (FileNotFoundException e)
		{
			System.out.println(e.getMessage());

		}
		finally
		{
			try
			{
				f.close();
			}
			catch (IOException e)
			{
				System.out.println("File not found");
				e.printStackTrace();
			}
		}

		return found;

	}

	public static void main(String[] args)
	{
		String user="";
		String pass="";


		try
		{
			BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));

			int i=0;
			boolean logged = false;
			while(i<5 && logged == false)
			{
				System.out.println("User: ");
				user = stdin.readLine();

				System.out.println("Password: ");
				pass = stdin.readLine();

				if(ValidateLogin(user, pass))
					{
						System.out.println("Acces permis!");
						logged = true;
					}
				else if (FindUser(user))
				{
					System.out.println("Parola gresita!");
					int j=0;
					boolean ok = false;
					while (j<3 && ok==false)
					{
						System.out.println("Password: ");
						pass = stdin.readLine();

						if(ValidateLogin(user, pass))
							ok=true;
						j++;
					}
					if (!ok)
						System.out.println("Cont blocat!");
				}
			i++;
			}
			if(!logged)
				System.out.println("Nu ai cont! Inregistreaza-te!");
		}
		catch(NumberFormatException ex)
		{
			System.out.println(ex.getMessage());
		}
		catch(IOException ex)
		{
			System.out.println(ex.getMessage());
		}
	}
}


import java.io.BufferedReader;  ex1
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;

public class Ex1
{
	static int[][] ReadMatrix()
	{
		int[][] mat = null;
		int rows = 0,cols = 0;

		BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));



		try
		{
			System.out.println("Number of rows: ");
			rows = Integer.parseInt(stdin.readLine());
			System.out.println("Number of cols: ");
			cols = Integer.parseInt(stdin.readLine());

			mat = new int[rows][cols];

			for(int i=0;i<rows;i++)
				for(int j=0;j<cols;j++)
				{
					System.out.println("mat["+i+"]["+j+"] = ");
					mat[i][j]=Integer.parseInt(stdin.readLine());
				}

		}
		catch (NumberFormatException e)
		{
			System.out.println("Cannot parseInt \n"+e.getMessage());
		}
		catch(NullPointerException e)
		{
			System.out.println(e.getMessage());
		}
		catch (IOException ex)
		{
			System.out.println(ex.getMessage());
		}


		return mat;
	}

	 static int[][] ReadMatrixFromFile(String fileName)
	{
		int [][] mat=null;
		int cols=0, rows =0;

		FileReader f =null;


		try
		{
		  f = new FileReader(fileName);
			Scanner s = new Scanner(f);

			rows = s.nextInt();
			cols = s.nextInt();

			mat = new int[rows][cols];

			int i=0,j=0;
			while(s.hasNextInt())
			{

				if(j<cols)
					{
						mat[i][j++] =s.nextInt();

					}
				else
				{
					j=0;
					i++;
					mat[i][j++] = s.nextInt();

				}
			}


		}
		catch(NumberFormatException ex)
		{
			System.out.println("Cannot parseInt \n"+ex.getMessage());
		}
		catch (FileNotFoundException e)
		{
			System.out.println("Cannot find file. \n"+e.getMessage());
		}
		catch (IOException e)
		{
			System.out.println(e.getMessage());
		}
		finally
		{
			try
			{
				f.close();
			}
			catch (IOException e)
			{
				System.out.println("File not found");
				e.printStackTrace();
			}
		}

		return mat;
	}

	static int[][] MultiplyMatrix(int[][] mat1,int[][] mat2)
	{
		int[][] result = null;

		try
		{


		if(mat1[0].length!=mat2.length)
		{
			System.out.println("Cannot multiply matrix.");
		}
		else
		{
			result = new int[mat1.length][mat2[0].length];

			for(int i=0;i<mat1.length;i++)
				for(int j=0;j<mat2[0].length;j++)
					for(int k=0;k<mat1[0].length;k++)
					{
						result[i][j] += mat1[i][k] * mat2[k][j];
					}
		}
		}
		catch(NullPointerException ex)
		{
			System.out.println("Matrix is null \n"+ex.getMessage());
		}

		return result;
	}

	static void DisplayMatrix(int[][] mat)
	{
		try
		{
		System.out.println("Matricea este : ");

		for (int i=0;i<mat.length;i++)
		{
			for(int j=0;j<mat[0].length;j++)
				System.out.print(mat[i][j]+" ");
			System.out.println();
		}
		}
		catch(NullPointerException ex)
		{
			System.out.println("Matrix is null \n"+ex.getMessage());
		}
	}

	static void WriteMatrixToFile(int[][] mat,String fileName)
	{
		FileWriter f = null;
		try
		{

			f = new FileWriter(fileName);

			for (int i=0;i<mat.length;i++)
				{
					for(int j=0;j<mat[0].length;j++)
					{
						String aux = String.valueOf(mat[i][j])+" ";
						f.append(aux);
					}
				f.append("\r\n");
				}
		}
		catch(NullPointerException ex)
		{
			System.out.println("Matrix is null \n"+ex.getMessage());
		}
		catch (IOException e)
		{
			System.out.println("Cannot find file \n"+e.getMessage());
		}
		finally
		{
			try
			{
				f.close();
			}
			catch (IOException e)
			{
				System.out.println(e.getMessage());
			}
		}
	}

	public static void main(String[] args)
	{
		int[][] mat1 = ReadMatrixFromFile("in.txt");
		DisplayMatrix(mat1);
		int[][] mat2 = ReadMatrix();
		DisplayMatrix(mat2);
		DisplayMatrix(MultiplyMatrix(mat1, mat2));
		WriteMatrixToFile(MultiplyMatrix(mat1, mat2),"out.txt");

	}
}