Compilare: user.c:6: warning: return type of ‘main’ is not ‘int’ user.c: In function ‘main’: user.c:21: warning: format ‘%d’ expects type ‘int’, but argument 2 has type ‘long int’ user.c:7: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:8: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c:11: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result