/in/foo.cc:16:17: error: 'acos' was not declared in this scope
   16 | const double PI=acos(-1);
      |                 ^~~~
/in/foo.cc: In function 'void FFT(C*, int)':
/in/foo.cc:30:14: error: 'cos' was not declared in this scope
   30 |         C wn(cos(2*PI/i),type*sin(2*PI/i));
      |              ^~~
/in/foo.cc:30:31: error: 'sin' was not declared in this scope
   30 |         C wn(cos(2*PI/i),type*sin(2*PI/i));
      |                               ^~~
/in/foo.cc: In function 'void init()':
/in/foo.cc:60:9: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   60 |         for(int j=1;j<=1200;j++) f[i+1][j]=((int)(a[j-1].r/4096+0.5))%mo;f[i+1][0]=1;
      |         ^~~
/in/foo.cc:60:74: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   60 |         for(int j=1;j<=1200;j++) f[i+1][j]=((int)(a[j-1].r/4096+0.5))%mo;f[i+1][0]=1;
      |                                                                          ^