View Compilation Error

0_0_23845192_26829.cpp: In function 'void FFT::DFT(FFT::Cp*, int)':
0_0_23845192_26829.cpp:24:19: error: 'pi' was not declared in this scope
    Cp wn=(Cp){cos(pi/i),sin(pi/i)};
                   ^
0_0_23845192_26829.cpp: In function 'int main()':
0_0_23845192_26829.cpp:77:24: error: too few arguments to function 'void FFT::calc(int*, int*, int*, int, int, int)'
     FFT::calc(f,g,h,n,n);
                        ^
0_0_23845192_26829.cpp:35:7: note: declared here
  void calc(int *A,int *B,int *C,int n,int m,int Mod){
       ^
0_0_23845192_26829.cpp:82:27: error: too few arguments to function 'void FFT::calc(int*, int*, int*, int, int, int)'
     FFT::calc(f,g,h,n<<1,n);
                           ^
0_0_23845192_26829.cpp:35:7: note: declared here
  void calc(int *A,int *B,int *C,int n,int m,int Mod){
       ^