View Compilation Error

0_0_27908351_11418.cpp: In function 'int main()':
0_0_27908351_11418.cpp:52:16: error: 'bit' was not declared in this scope
         getrev(bit);fft(a,s,1);fft(b,s,1);//dft
                ^
0_0_27908351_11418.cpp:52:19: error: 'getrev' was not declared in this scope
         getrev(bit);fft(a,s,1);fft(b,s,1);//dft
                   ^