### Player VS Computer

    1. game mode select
    2. player vs computer
    3. player login (username and password)
    4. Game run (player vs computer)
    5. Game finish
    6. Show ranking
    7. Back to start

```mermaid
graph TD;
    A[Game Mode Select] --> B[Player vs Computer];
    B --> C["Player Login (Username and Password)"];
    C --> D["Game Run (Player vs Computer)"];
    D --> E[Game Finish];
    E --> F[Show Ranking?];
    F --> H[show ranking to user];
    H --> G[Back to Start];
    F --> G[Back to Start];
```

### Player VS Player

    1. game mode select
    2. player vs computer
    3. player1 login (username and password)
    3. player2 login (username and password)
    4. Game run (player vs computer)
    5. Game finish
    6. Show ranking
    7. Back to start

```mermaid
graph TD;
    A[Start] --> B[Game Mode Select];
    B --> C[Player VS Computer];
    C --> D["Player1 Login (username and password)"];
    D --> E["Player2 Login (username and password)"];
    E --> F["Game Run (Player VS Computer)"];
    F --> G[Game Finish];
    G --> H[Show Ranking?];
    H --> J[show ranking to user];
    H --> I[Back to Start];
    J --> I;
    I --> A;
```

### show ranking

    1. read ranking
    2. show to user

```mermaid
graph TD;
    A[Start] --> B[Read Ranking];
    B --> C[Show Ranking to User];
    C --> D[End];
```

### change password

    1. open password file `ac.txt`
    2. read passwords
    3. find current user
    4. change password when username match
    5. save to file

```mermaid
graph TD;
    A[Start] --> B["Open Password File ac.txt"];
    B --> C[Read Passwords];
    C --> D[Find Current User];
    D -->|Username Match| E[Change Password];
    D -->|Username Not Found| F[Display Error Message];
    E --> G[Save to File];
    G --> H[End];
    F --> H[End];
```


### create player

    1. get username and password from user
    2. check if username or password is empty
    3. show missing to user if empty
    4. username and password ok
    5. write to account file


```mermaid
graph TD;
    A[Start] --> B[Get Username and Password from User];
    B --> C[Check if Username or Password is Empty];
    C -->|Username or Password is Empty| D[Show Missing Fields to User];
    C -->|Username and Password are Not Empty| E[Write to Account File];
    D --> F[End];
    E --> F[End];
```


### delete player

    1. open password file `ac.txt`
    2. read username 
    3. if username found in file
    4. delete user
    5. write change to file


```mermaid
graph TD;
    A[Start] --> B["Open Password File ac.txt"];
    B --> C[Read Username];
    C --> D[Username Found in File?];
    D -->|Yes| E[Delete User];
    D -->|No| F[Display Error Message];
    E --> G[Write Changes to File];
    G --> H[End];
    F --> H[End];
    A@{ shape: circle}
    H@{ shape: circle}
    D@{ shape: diamond }
```