Compilare: user.cpp: In function ‘int main()’: user.cpp:12:9: warning: suggest parentheses around ‘+’ inside ‘>>’ [-Wparentheses] f>>s+1; ^ user.cpp:14:15: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[s[i]]++; ^ user.cpp:17:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(ok[s[i]]==0){ ^ user.cpp:18:47: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(vf>0&&st[vf]>s[i]&&fr[st[vf]]>0){ ^ user.cpp:19:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] ok[st[vf]]=0;fr[st[vf]]--; ^ user.cpp:19:39: warning: array subscript has type ‘char’ [-Wchar-subscripts] ok[st[vf]]=0;fr[st[vf]]--; ^ user.cpp:25:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] ok[s[i]]=1; ^ user.cpp:30:18: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[s[i]]--; ^