Compilare: user.c: In function ‘main’: user.c:5:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("dmin2.in","r",stdin),freopen("dmin2.out","w",stdout),scanf("%lld%lld",&n,&m),o=m; ^ user.c:5:39: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("dmin2.in","r",stdin),freopen("dmin2.out","w",stdout),scanf("%lld%lld",&n,&m),o=m; ^ user.c:5:69: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] freopen("dmin2.in","r",stdin),freopen("dmin2.out","w",stdout),scanf("%lld%lld",&n,&m),o=m; ^ user.c:7:11: warning: ignoring return value of ‘gets’, declared with attribute warn_unused_result [-Wunused-result] gets(t); ^ /tmp/cc3J3jpo.o: In function `main': user.c:(.text.startup+0x88): warning: the `gets' function is dangerous and should not be used.