/in/foo.cc: In function 'int main()':
/in/foo.cc:120:31: warning: 'validNum' may be used uninitialized in this function [-Wmaybe-uninitialized]
     avgNights = totalNights / double(validNum);
                               ^~~~~~~~~~~~~~~~
/in/foo.cc:120:15: warning: 'totalNights' may be used uninitialized in this function [-Wmaybe-uninitialized]
     avgNights = totalNights / double(validNum);
     ~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~