Compilare: user.cpp: In function ‘int main()’: user.cpp:13:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<=s.size()-1;i++) ~^~~~~~~~~~~~ user.cpp:14:16: warning: array subscript has type ‘char’ [-Wchar-subscripts] { fa[s[i]]++; ^ user.cpp:17:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(s[i+1]!=s[i]||i==s.size()-1){fout<<s[i]<<fa[s[i]];fa[s[i]]=0;} ~^~~~~~~~~~~~ user.cpp:17:60: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(s[i+1]!=s[i]||i==s.size()-1){fout<<s[i]<<fa[s[i]];fa[s[i]]=0;} ^ user.cpp:17:69: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(s[i+1]!=s[i]||i==s.size()-1){fout<<s[i]<<fa[s[i]];fa[s[i]]=0;} ^