Compilare: main.cpp: In member function 'bool Bigint::operator<(Bigint)': main.cpp:47:20: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 47 | if(a.size()!=b.size()) return a.size()*sign<b.size()*sign; | ~~~~~~~~^~~~~~~~~~ main.cpp:47:52: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 47 | if(a.size()!=b.size()) return a.size()*sign<b.size()*sign; | ~~~~~~~~~~~~~^~~~~~~~~~~~~~ main.cpp: In member function 'Bigint Bigint::operator+(Bigint)': main.cpp:67:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 67 | for(int i=0, carry=0; i<a.size() || i<b.size() || carry; i++){ | ~^~~~~~~~~ main.cpp:68:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 68 | if (i<a.size()) carry+=a[i]-'0'; | ~^~~~~~~~~ main.cpp: In member function 'Bigint Bigint::operator-(Bigint)': main.cpp:88:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 88 | for(int i=0,borrow=0; i<a.size(); i++) { | ~^~~~~~~~~ main.cpp: In member function 'Bigint Bigint::operator*(Bigint)': main.cpp:105:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 105 | for(int i=0, k=a[i]; i<a.size(); i++, k=a[i]) { | ~^~~~~~~~~ main.cpp: In member function 'Bigint Bigint::operator/(Bigint)': main.cpp:120:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 120 | for(int j=0; j<a.size(); j++) d.a += "0"; | ~^~~~~~~~~