Merge branch 'master' into fix-pr-22

Author: phrdang

.github/workflows/java.yml renamed to .github/java.yml

@@ -1,4 +1,4 @@
-package com.codefortomorrow.advanced.chapter13.practice;
+package com.codefortomorrow.advanced.chapter13.solutions;
 
 /*
 Implement the iterative code as a recursive

src/com/codefortomorrow/advanced/chapter13/solutions/NegativeSum.java

@@ -0,0 +1,62 @@
+package com.codefortomorrow.advanced.chapter14.practice;
+
+/*
+Create the following classes that simply extend the `Exception` class: 
+
+- `InvalidUsernameException`
+- `InvalidPasswordException`
+- `InvalidAgeException`
+- `PasswordMismatchException`
+
+In the `Account` class, code a method called `createAccount` that takes a `username`, `age`,
+`password`, and `confirmPassword` as parameters. 
+
+In `createAccount`, throw an:
+
+- `InvalidUsernameException` - if the given username is <4 or >10 characters.
+- `InvalidPasswordException` - if the given password is <4 or >10 characters.
+- `InvalidAgeException` - if the given age is <18.
+- `PasswordMismatchException` - if the given password does not match the given confirm password.
+
+In your `main` method (within the `Account` class):
+
+- To simulate the creation of an account online, prompt the user to enter their username, age,
+  password, and their password again (to confirm).
+- Call the `createAccount` method continuously with the user's input and use `try`/`catch` to
+  handle the possible exceptions and print the appropriate error message. (You can assume that
+  the user input will only throw at most 1 exception.)
+- Keep asking the user for input until the account is created successfully.
+
+Example output:
+
+```
+Welcome to Account Creation!
+Enter username (4 to 10 characters): hi
+Enter age: 18
+Enter password (4 to 10 characters): thisislong
+Confirm password (4 to 10 characters): thisislong
+Invalid username.
+Enter username (4 to 10 characters): four
+Enter age: 18
+Enter password (4 to 10 characters): thisislong
+Confirm password (4 to 10 characters): thisislong
+Account created successfully!
+```
+*/
+
+public class Account {
+
+    public static void main(String[] args) {
+        // Write your code here
+    }
+
+    public static void createAccount(
+        String username,
+        int age,
+        String password,
+        String confirmPassword
+    ) {
+        // Write your code here
+    }
+}
+// Write exception classes here

src/com/codefortomorrow/advanced/chapter14/practice/Account.java

@@ -1,7 +1,5 @@
 package com.codefortomorrow.advanced.chapter14.practice;
 
-import java.io.*;
-
 /*
 The file “numbers.txt” has 100 random numbers
 (one on each line). Use file i/o to find the

src/com/codefortomorrow/advanced/chapter14/practice/Average.java

@@ -1,7 +1,5 @@
 package com.codefortomorrow.advanced.chapter14.practice;
 
-import java.io.*;
-
 /*
 Practice: Use File I/O to compare two files lexicographically.
 Lexicographical order is very similar to alphabetical order,