Compilare: user.c: In function ‘main’: user.c:18:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] f[v[i]]++; ^ user.c:19:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(f[v[i]]==1) ^ user.c:27:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] f[v[j]]--; ^ user.c:28:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(f[v[j]]==0) ^ user.c:33:13: warning: array subscript has type ‘char’ [-Wchar-subscripts] f[v[i]]++; ^ user.c:34:13: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(f[v[i]]==1) ^ user.c:9:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("teatru.in","r",stdin); ^ user.c:10:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("teatru.out","w",stdout); ^ user.c:11:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&z,&c); ^ user.c:13:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s",v); ^