added java files

Problem1.java

+import java.io.*;
+import java.util.*;
+
+public class Problem1 {
+	public static void main(String[] args) {
+		int sum = 0;
+		for (String x : args) {
+			int y = Integer.parseInt(x);
+			sum = sum + y;
+		}
+		System.out.println(args.length + ", " + sum);
+	}
+}
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Problem2.java

+import java.io.*;
+import java.util.*;
+
+public class Problem2 {
+	static double mean(int[] a) {
+		int sum = 0;
+		for (int x : a)
+			sum += x;
+		return sum / a.length;
+	}
+	static double stddev(int[] a) {
+		int sum = 0;
+		double m = mean(a);
+		for (int x : a) 
+			sum += Math.pow(x - m, 2);
+		return Math.sqrt(sum / (a.length - 1));
+	}
+	public static void main(String[] args) throws IOException {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		int n = Integer.parseInt(br.readLine());
+		int[] arr = new int[n];
+		Random randomGenerator = new Random();
+		for (int i = 0; i < n; i++)
+			arr[i] = randomGenerator.nextInt(100) + 1;  //random no.s between 1-100
+		System.out.println("Mean = " + mean(arr));
+		System.out.println("Standard deviation = " + stddev(arr));
+		br.close();
+	}
+}
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Problem3.java

+import java.io.*;
+import java.util.*;
+
+public class Problem3 {
+	public static void main(String[] args) throws IOException {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		System.out.print("Input: ");
+		String inp = br.readLine();
+		String[] inp_temp = inp.split(",");
+		String txt = inp_temp[0];
+		int a = Integer.parseInt(inp_temp[1].trim());
+		int b = Integer.parseInt(inp_temp[2].trim());
+		System.out.println("Output: " + txt.substring(a, b+1));
+		br.close();
+	}
+}
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Problem4.java

+import java.io.*;
+import java.util.*;
+import java.text.*;
+
+public class solution {
+	public static class Runtime implements Runnable {
+		public void run() {
+			Date d = new Date();
+			SimpleDateFormat s = new SimpleDateFormat("HH:mm:ss");
+			String q = s.format(d);
+			System.out.printf("\r %s", q);
+		}
+	}
+	public static void main(String[] args) {
+		Runtime r = new Runtime();
+		Thread t = new Thread(r);
+		try {
+			while (true) {
+				t.run();
+				t.sleep(1000);
+			}
+		}
+		catch(InterruptedException e) {
+			System.out.println(e);
+		}
+	}
+}
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Problem5.java

+import java.io.*;
+import java.util.*;
+
+public class Problem5 {
+	static int binarySearch(String[] arr, String key) {
+		Arrays.sort(arr);
+		int l = 0;
+		int h = arr.length - 1;
+		int mid = 0;
+		while (l <= h) {
+			mid = (l + h) / 2;
+			if (arr[mid].compareTo(key) < 0)
+				l = mid + 1;
+			else if (arr[mid].compareTo(key) > 0)
+				h = mid - 1;
+			else
+				return mid;
+		}
+		return -1;
+	}
+	static String readfile(String filename) throws IOException {
+		BufferedReader input = new BufferedReader(new FileReader(filename));
+		StringBuilder s = new StringBuilder();
+		String line = input.readLine();
+		while (line != null) {
+			s.append(line);
+			s.append("\n");
+			line = input.readLine();
+		}
+		input.close();
+		return s.toString();
+	}
+	public static void main(String[] args) throws IOException {
+		BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
+		String file = input.readLine();
+		String file_c = readfile(file);
+		String splitter = "[ .,?!\n]+";
+		String[] tokens = file_c.split(splitter);
+		String[] stop_words = {"and", "the", "is", "in", "at", "of", "his", "her", "him"};
+		ArrayList<String> al = new ArrayList<String>();
+		for (String x : tokens)
+			if (binarySearch(stop_words, x.toLowerCase()) == -1)
+				al.add(x);
+		Set<String> s = new HashSet<String>(al);
+		for (String y : s)
+			System.out.println(y + " = " + Collections.frequency(al, y));
+		input.close();
+	}
+}
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Problem6.java

+import javax.swing.*;
+import java.awt.event.*;
+
+public class Problem6 {
+	public static void main(String[] args) {
+		//declaraing all components of the window
+		JFrame window = new JFrame("Program6");
+		JTextField userid = new JTextField();
+		JPasswordField passw = new JPasswordField();
+		JButton login = new JButton("Login");
+		JButton reset = new JButton("Reset");
+		JLabel usnm = new JLabel("User Id: ");
+		JLabel pswd = new JLabel("Password: ");
+
+		//setting the size of the components
+		userid.setBounds(150,50,100,25);
+		passw.setBounds(150,100,100,25);
+		login.setBounds(100,200,100,30);
+		reset.setBounds(100,250,100,30);
+		usnm.setBounds(50,50,100,25);
+		pswd.setBounds(50,100,100,25);
+		window.setSize(300,400);
+
+		//action events for the buttons
+		login.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent e) {
+				if (userid.getText().isEmpty() || passw.getText().isEmpty())
+					JOptionPane.showMessageDialog(null, "Text fields are empty !", "Message", JOptionPane.INFORMATION_MESSAGE);
+				else
+					JOptionPane.showMessageDialog(null, "Text fields are not empty !", "Message", JOptionPane.INFORMATION_MESSAGE);
+			}
+		});
+
+		reset.addActionListener(new ActionListener() {
+			public void actionPerformed(ActionEvent e) {
+				userid.setText("");
+				passw.setText("");
+			}
+		});
+
+		//adding the components to the main window
+		window.add(usnm);
+		window.add(pswd);
+		window.add(userid);
+		window.add(passw);
+		window.add(login);
+		window.add(reset);
+
+		//Some window operations
+		window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+		window.setLocationRelativeTo(null);
+		window.setLayout(null);
+		window.setVisible(true);
+	}
+}
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