Compilare: main.cpp: In function 'BigInt add(const BigInt&, const BigInt&)': main.cpp:34:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 34 | if (i < a.digits.size()) sum += a.digits[i]; | ~~^~~~~~~~~~~~~~~~~ main.cpp:35:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 35 | if (i < b.digits.size()) sum += b.digits[i]; | ~~^~~~~~~~~~~~~~~~~ main.cpp: In function 'BigInt mul(const BigInt&, int)': main.cpp:47:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 47 | for (int i = 0; i < a.digits.size() || carry; i++) { | ~~^~~~~~~~~~~~~~~~~ main.cpp:49:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 49 | if (i < a.digits.size()) cur += 1LL * a.digits[i] * b; | ~~^~~~~~~~~~~~~~~~~