/in/foo.c:4:17: error: variably modified 'fa' at file scope
 int n,m,ans,cnt,fa[N];
                 ^~
/in/foo.c:7:2: error: variably modified 'e' at file scope
 }e[M];
  ^
/in/foo.c:16:1: error: unknown type name 'bool'
 bool merge(int u,int v){
 ^~~~
/in/foo.c: In function 'quicksort':
/in/foo.c:28:2: error: unknown type name 'Edge'
  Edge t;
  ^~~~
/in/foo.c:28:2: note: use 'struct' keyword to refer to the type
/in/foo.c:35:6: error: incompatible types when assigning to type 'int' from type 'struct Edge'
    t = e[i];
      ^
/in/foo.c:37:9: error: incompatible types when assigning to type 'struct Edge' from type 'int'
    e[j] = t;
         ^
/in/foo.c:40:4: error: incompatible types when assigning to type 'int' from type 'struct Edge'
  t = e[lef];
    ^
/in/foo.c:42:7: error: incompatible types when assigning to type 'struct Edge' from type 'int'
  e[i] = t;
       ^