Compilare: user.c: In function ‘main’: user.c:50:11: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen ("date.in", "r", stdin); ^ user.c:53:9: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &n, &m); ^ user.c:58:11: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d", &from, &to, &cost); ^