Your input file needs to be in the same directory as the executable if you don't supply a full path to it.
In the left pane of Qt Creator click on "Projects", near the top "Build" should be highlighted, if not click on it. Under "General", if "Shadow build" is checked, you can either uncheck it and the project will be built in your source directory where your input file resides or leave it checked and copy your input file to the build directory.
Quote:
instead of opening a separate terminal
|
Again under "Projects", near the top click "Run" then uncheck "Run in terminal"
Edit: Reread your post. Sometimes I wonder about my reading comprehension. If "Run in terminal" is unchecked, the prompt for the file name will show up in the application output tab but Qt Creator won't accept input. So unchecking "Run in terminal" will not work for programs requiring user input.