Compilare: main.cpp: In member function 'int BigInt::operator[](int) const': main.cpp:120:22: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'const int' [-Wsign-compare] 120 | if(digits.size() <= index || index < 0) | ~~~~~~~~~~~~~~^~~~~~~~ main.cpp: In function 'BigInt& operator/=(BigInt&, const BigInt&)': main.cpp:287:24: warning: unused variable 'm' [-Wunused-variable] 287 | int n = Length(a), m = Length(b); | ^ main.cpp: In function 'BigInt& operator%=(BigInt&, const BigInt&)': main.cpp:324:24: warning: unused variable 'm' [-Wunused-variable] 324 | int n = Length(a), m = Length(b); | ^ main.cpp: In function 'void backt(int)': main.cpp:463:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 463 | for(int i=0; i<fs.size(); i++) | ~^~~~~~~~~~