Compilare: user.c: In function ‘main’: user.c:21:2: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen(in, "rt", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~ user.c:22:2: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen(out, "wt", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:25:2: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^~~~~~~~~~~~~~~ user.c:30:3: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &v[i].a, &v[i].b); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~