View Compilation Error

0_0_27775911_10901.cpp: In function 'int main()':
0_0_27775911_10901.cpp:19:43: error: 'i' was not declared in this scope
                                         a[i]=double(j[i])/f(i);
                                           ^
0_0_27775911_10901.cpp:19:62: error: 'f' cannot be used as a function
                                         a[i]=double(j[i])/f(i);
                                                              ^