Compilare: user.c: In function ‘main’: user.c:9:2: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen(in, "rt", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~ user.c:10:2: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen(out, "wt", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:13:2: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^~~~~~~~~~~~~~~ user.c:14:2: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &M); ^~~~~~~~~~~~~~~ user.c:18:3: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^~~~~~~~~~~~~~~~~~ user.c:23:3: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &aux); ^~~~~~~~~~~~~~~~~ user.c:24:3: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a); ^~~~~~~~~~~~~~~ user.c:25:3: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &b); ^~~~~~~~~~~~~~~