Compilare: main.c: In function 'main': main.c:6:5: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("oo.in","r",stdin),freopen("oo.out","w",stdout),scanf("%d",&n); ^~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:6:32: warning: ignoring return value of 'freopen', declared with attribute warn_unused_result [-Wunused-result] freopen("oo.in","r",stdin),freopen("oo.out","w",stdout),scanf("%d",&n); ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ main.c:6:61: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] freopen("oo.in","r",stdin),freopen("oo.out","w",stdout),scanf("%d",&n); ^~~~~~~~~~~~~~ main.c:8:9: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",a+i); ^~~~~~~~~~~~~~~