function in c++

while i am using int function in c one extra output is coming

can we use function overloading and default arguments at same time in c++

Uncaught Error: Call to a member function prepare() on null in C:\xampp\htdocs\facultate\CosCump\product.php:5 Stack trace: #0 {main} thrown in C:\xampp\htdocs\facultate\CosCump\product.php on line 5

Fatal error: Uncaught Error: Call to undefined function mysqli_connect() in C:\Users\Joalu\Desktop\new.php:3 Stack trace: #0 {main}

Write a function called clean that takes a C++ string as input and removes any characters in the string that are not letters except for space blanks.

cv2.error: opencv(4.2.0) c:\projects\opencv-python\opencv\modules\imgproc\src\color.cpp:182: error: (-215:assertion failed) !_src.empty() in function 'cv::cvtcolor'

opencv(4.5.1) c:\users\appveyor\appdata\local\temp\1\pip-req-build-kh7iq4w7\opencv\modules\imgproc\src\resize.cpp:4051: error: (-215:assertion failed) !ssize.empty() in function

opencv(4.4.0) c:\users\appveyor\appdata\local\temp\1\pip-req-build-71670poj\opencv\modules\imgproc\src\color.cpp:182: error: (-215:assertion failed) !_src.empty() in function

function that, given the number of rows N and a list of reserved seats as string S returns the maximum of four-person families that can be seated in the remaining unreserved seats c++