Compilare: user.c: In function ‘quicksort’: user.c:18:38: warning: operation on ‘*(a + (sizetype)((unsigned int)iR * 4u))’ may be undefined [-Wsequence-point] {a[iL]=a[iL]+a[iR]-(a[iR]=a[iL]); ^ user.c:8:9: warning: unused variable ‘aux’ [-Wunused-variable] int aux; ^ user.c: At top level: user.c:27:1: warning: return type defaults to ‘int’ [enabled by default] main() ^ user.c: In function ‘main’: user.c:34:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%i %i %i\n",&N,&A,&B); ^ user.c:35:10: warning: ignoring return value of ‘fgets’, declared with attribute warn_unused_result [-Wunused-result] fgets(s,100,f); ^