Compilare: main.cpp: In member function 'big_int big_int::operator+(const big_int&) const': main.cpp:178:21: warning: comparison of integer expressions of different signedness: 'int' and 'const long unsigned int' [-Wsign-compare] 178 | for (i = 0; i < std::min(digits.size(), b.digits.size()); ++i) | ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp:185:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 185 | for (; i < digits.size(); ++i) | ~~^~~~~~~~~~~~~~~ main.cpp:192:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 192 | for (; i < b.digits.size(); ++i) | ~~^~~~~~~~~~~~~~~~~ main.cpp: In member function 'big_int big_int::operator-(const big_int&) const': main.cpp:229:21: warning: comparison of integer expressions of different signedness: 'int' and 'const long unsigned int' [-Wsign-compare] 229 | for (i = 0; i < std::min(digits.size(), b.digits.size()); ++i) | ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp:243:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 243 | for (; i < digits.size(); ++i) | ~~^~~~~~~~~~~~~~~ main.cpp: In member function 'big_int big_int::operator*(const big_int&) const': main.cpp:278:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 278 | for (i = 0; i < digits.size(); ++i) | ~~^~~~~~~~~~~~~~~ main.cpp:282:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 282 | for (j = 0; j < b.digits.size(); ++j) | ~~^~~~~~~~~~~~~~~~~ main.cpp: In function 'bool operator<(const big_int&, const big_int&)': main.cpp:125:3: warning: control reaches end of non-void function [-Wreturn-type] 125 | } | ^ main.cpp: In member function 'big_int big_int::operator-(const big_int&) const': main.cpp:262:3: warning: control reaches end of non-void function [-Wreturn-type] 262 | } | ^ main.cpp: In member function 'big_int big_int::operator+(const big_int&) const': main.cpp:204:3: warning: control reaches end of non-void function [-Wreturn-type] 204 | } | ^