How to configure and run the project once the idea is open?

To set up and run an IntelliJ IDEA project, you can follow these steps: 1. Open the IntelliJ IDEA software, click on “Open” on the main interface or select the “Open” option in the “File” menu. 2. In the pop-up dialog, choose the root directory of the project you want to open, then click “OK”. 3. IDEA will load and open your project. Once the project is open, you can see the project structure and file list. 4. Next, you may need to configure some properties or dependencies of the project. You can open the project settings by clicking on the “Project Structure” option in the “File” menu. 5. In the project settings, you can configure the SDK and modules of the project, add dependencies, set compilation options, etc. After completing the settings, click “OK” to save the changes and close the dialog. 6. Make sure your project includes an entry class with the main method as the starting point of the program. 7. If you want to run the entire project, you can choose the “Run” option in the menu or use the shortcut Shift + F10. This will compile and run your project. 8. If you only want to run a single class file in the project, you can open that class file in the editor and then click the green triangle button on the left side of the editor to run it. 9. IDEA will display the output of the program in the run window at the bottom. This way, you have successfully set up and run your idea project.