/in/compound.cpp:4:8: error: prototype for 'double Compound::calculateMolarMass(int*, int)' does not match any in class 'Compound'
 double Compound:: calculateMolarMass(int* arr, int num) {
        ^~~~~~~~
In file included from /in/compound.cpp:1:0:
/in/compile/compound.h:32:16: error: candidate is: double Compound::calculateMolarMass()
         double calculateMolarMass();
                ^~~~~~~~~~~~~~~~~~
/in/compound.cpp:20:8: error: prototype for 'std::__cxx11::string Compound::toString(int*, int)' does not match any in class 'Compound'
 string Compound:: toString(int* arr, int num){
        ^~~~~~~~
In file included from /in/compound.cpp:1:0:
/in/compile/compound.h:33:16: error: candidate is: std::__cxx11::string Compound::toString()
         string toString();
                ^~~~~~~~