Compilare: user.cpp: In member function 'BigInt& BigInt::operator+=(const BigInt&)': user.cpp:29: warning: comparison between signed and unsigned integer expressions user.cpp:28: warning: unused variable 't' user.cpp: In member function 'BigInt& BigInt::operator+=(long long int)': user.cpp:48: warning: comparison between signed and unsigned integer expressions user.cpp:47: warning: unused variable 't' user.cpp: In function 'int main()': user.cpp:69: warning: unused variable 'k' user.cpp: In member function 'BigInt& BigInt::operator+=(long long int)': user.cpp:53: warning: control reaches end of non-void function user.cpp: In member function 'BigInt& BigInt::operator+=(const BigInt&)': user.cpp:39: warning: control reaches end of non-void function