Compilare: user.cpp: In function ‘void labelize()’: user.cpp:25:18: warning: unused variable ‘xn’ [-Wunused-variable] int cnt = 0, xn, yn; ^ user.cpp:25:22: warning: unused variable ‘yn’ [-Wunused-variable] int cnt = 0, xn, yn; ^ user.cpp: In function ‘int main()’: user.cpp:136:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < g[x].size(); ++i) ^