Error(s):

1154457348/source.c:6:6: error: stray ‘\342’ in program
 void ∗count ( void ∗arg ) {             /*cuerpo de cada hebra*/
      ^
1154457348/source.c:6:7: error: stray ‘\210’ in program
 void ∗count ( void ∗arg ) {             /*cuerpo de cada hebra*/
       ^
1154457348/source.c:6:8: error: stray ‘\227’ in program
 void ∗count ( void ∗arg ) {             /*cuerpo de cada hebra*/
        ^
1154457348/source.c:6:22: error: stray ‘\342’ in program
 void ∗count ( void ∗arg ) {             /*cuerpo de cada hebra*/
                      ^
1154457348/source.c:6:23: error: stray ‘\210’ in program
 void ∗count ( void ∗arg ) {             /*cuerpo de cada hebra*/
                       ^
1154457348/source.c:6:24: error: stray ‘\227’ in program
 void ∗count ( void ∗arg ) {             /*cuerpo de cada hebra*/
                        ^
1154457348/source.c:6:25: error: parameter 1 (‘arg’) has incomplete type
 void ∗count ( void ∗arg ) {             /*cuerpo de cada hebra*/
                         ^~~
1154457348/source.c: In function ‘count’:
1154457348/source.c:10:11: warning: ‘return’ with a value, in function returning void
    return NULL ;
           ^~~~
1154457348/source.c:6:9: note: declared here
 void ∗count ( void ∗arg ) {             /*cuerpo de cada hebra*/
         ^~~~~
1154457348/source.c: In function ‘main’:
1154457348/source.c:17:46: warning: passing argument 3 of ‘pthread_create’ from incompatible pointer type [-Wincompatible-pointer-types]
             pthread_create (&tids[i] , NULL, count , NULL ) ;
                                              ^~~~~
In file included from 1154457348/source.c:4:0:
/usr/include/pthread.h:234:12: note: expected ‘void * (*)(void *)’ but argument is of type ‘void (*)()’
 extern int pthread_create (pthread_t *__restrict __newthread,
            ^~~~~~~~~~~~~~
1154457348/source.c:19:10: error: ‘pthread’ undeclared (first use in this function); did you mean ‘pthread_t’?
          pthread _join ( tids[ i ] , NULL ) ;
          ^~~~~~~
          pthread_t
1154457348/source.c:19:10: note: each undeclared identifier is reported only once for each function it appears in
1154457348/source.c:19:18: error: expected ‘;’ before ‘_join’
          pthread _join ( tids[ i ] , NULL ) ;
                  ^~~~~