Compilare: user.cpp: In function ‘int main()’: user.cpp:12:9: warning: suggest parentheses around ‘+’ inside ‘>>’ [-Wparentheses] f>>s+1; ^ user.cpp:14:16: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[s[i]]++; ^ user.cpp:18:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(ok[s[i]]==0) ^ user.cpp:20:47: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(vf>0&&st[vf]>s[i]&&fr[st[vf]]>1) ^ user.cpp:22:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] ok[st[vf]]=0; ^ user.cpp:23:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[st[vf]]--; ^ user.cpp:29:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] ok[s[i]]=1; ^