foo.cc: In function 'BigInt operator*(BigInt&, int)':
foo.cc:23:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |   for (int i = 0; i < A.v.size() || t; i++)
      |                   ~~^~~~~~~~~~~~
foo.cc:25:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   25 |    if (i < A.v.size())t += A.v[i] * b;
      |        ~~^~~~~~~~~~~~
foo.cc: In function 'BigInt operator+(BigInt&, BigInt&)':
foo.cc:37:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |   for (int i = 0; i < A.v.size(); i++)
      |                   ~~^~~~~~~~~~~~
foo.cc:40:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |    if (i < B.v.size())t += B.v[i];
      |        ~~^~~~~~~~~~~~
foo.cc: In member function 'bool BigInt::operator<(BigInt&)':
foo.cc:61:2: warning: control reaches end of non-void function [-Wreturn-type]
   61 |  }
      |  ^

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