View Compilation Error

0_0_26447294_8826.cpp: In function 'void fft(plex*, int, int)':
0_0_26447294_8826.cpp:4:20: error: expected ')' before ';' token
 #define PI acos(-1);
                    ^
0_0_26447294_8826.cpp:42:23: note: in expansion of macro 'PI'
     plex wn(cos(-on*2*PI/h), sin(-on*2*PI/h));
                       ^
0_0_26447294_8826.cpp:42:25: error: expected primary-expression before '/' token
     plex wn(cos(-on*2*PI/h), sin(-on*2*PI/h));
                         ^
0_0_26447294_8826.cpp:42:42: error: expected primary-expression before '/' token
     plex wn(cos(-on*2*PI/h), sin(-on*2*PI/h));
                                          ^
0_0_26447294_8826.cpp: In function 'int main()':
0_0_26447294_8826.cpp:89:17: error: ISO C++ forbids comparison between pointer and integer [-fpermissive]
       if(ans >= 10)
                 ^