Compilare: user.cpp: In function ‘int exe(std::string)’: user.cpp:29:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < s.size(); i++)if(s[i] == 'E')return 1; ^ user.cpp: In function ‘void dfs(int)’: user.cpp:34:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < v[nod].size(); i++) ^ user.cpp: In function ‘int nre(std::string)’: user.cpp:48:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < s.size(); i++)if(s[i] == 'E')nr++; ^ user.cpp: In function ‘int calc(std::string)’: user.cpp:64:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size(); i++) ^