View Compilation Error

0_0_37824056_15785.cpp: In member function 'void Poly::operator^=(int&)':
0_0_37824056_15785.cpp:162:5: error: request for member 'resize' in '((Poly*)this)->Poly::a', which is of non-class type 'int*'
   a.resize(n);
     ^
0_0_37824056_15785.cpp: In function 'Poly cal(int, int)':
0_0_37824056_15785.cpp:181:8: error: request for member 'push_back' in 'x.Poly::a', which is of non-class type 'int*'
    x.a.push_back(qiu(h[l], j));
        ^
0_0_37824056_15785.cpp:185:7: error: request for member 'resize' in 'x.Poly::a', which is of non-class type 'int*'
   x.a.resize(len);
       ^