Compilare: user.c: In function ‘main’: user.c:5:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("harddp.in", "r", stdin); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:6:5: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("harddp.out", "w", stdout); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ user.c:10:5: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i", &t); ^~~~~~~~~~~~~~~ user.c:13:9: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i", &n); ^~~~~~~~~~~~~~~ user.c:14:9: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s", A); ^~~~~~~~~~~~~~