Compilare: user.c: In function ‘main’: user.c:17:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] frecv[v[i]]++; ^ user.c:21:9: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(inst[v[i]]==0){ ^ user.c:22:13: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(last>0 && st[last-1]>=v[i] && frecv[st[last-1]]>1){ ^ user.c:23:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] frecv[st[last-1]]--; ^ user.c:24:17: warning: array subscript has type ‘char’ [-Wchar-subscripts] inst[st[last-1]]=0; ^ user.c:28:13: warning: array subscript has type ‘char’ [-Wchar-subscripts] inst[v[i]]=1; ^ user.c:31:13: warning: array subscript has type ‘char’ [-Wchar-subscripts] frecv[v[i]]--; ^ user.c:13:11: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d", &n); ^