Compilare: user.c: In function ‘adunare_main’: user.c:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:6: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:9: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result user.c: In function ‘cmmdc_main’: user.c:24: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:25: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result user.c:27: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result