Compilare: user.c: In function ‘main’: user.c:13:6: warning: implicit declaration of function ‘cmmdc’ [-Wimplicit-function-declaration] printf("%d\n", cmmdc(a, b)); ^ user.c:6:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("eculid2.in", "r", stdin); ^ user.c:7:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("euclid2.out", "w", stdout); ^ user.c:9:7: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &T); ^ user.c:12:11: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &b); ^