Compilare: user.c: In function ‘back’: user.c:13:6: warning: unused variable ‘q’ [-Wunused-variable] int q; ^ user.c:12:6: warning: unused variable ‘p’ [-Wunused-variable] int p; ^ user.c: In function ‘main’: user.c:61:9: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("cmlsc.in", "r", stdin); ^ user.c:64:7: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &M, &N); ^ user.c:66:8: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i]); ^ user.c:68:8: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &b[i]); ^