Compilare: user.cpp: In function ‘int main()’: user.cpp:10:9: warning: suggest parentheses around ‘+’ inside ‘>>’ [-Wparentheses] f>>S+1; ^ user.cpp:12:16: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[S[i]]++; ^ user.cpp:15:20: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(viz[S[i]]==0){ ^ user.cpp:16:47: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(S[i]<st[vf]&&vf>0&&fr[st[vf]]>=1){ ^ user.cpp:17:27: warning: array subscript has type ‘char’ [-Wchar-subscripts] viz[st[vf]]=0; ^ user.cpp:20:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] viz[S[i]]=1; ^ user.cpp:24:16: warning: array subscript has type ‘char’ [-Wchar-subscripts] fr[S[i]]--; ^