Compilare: user.cpp: In function ‘void label()’: user.cpp:38:9: warning: unused variable ‘xn’ [-Wunused-variable] int xn, yn, cnt = 0; ^ user.cpp:38:13: warning: unused variable ‘yn’ [-Wunused-variable] int xn, yn, cnt = 0; ^ user.cpp: In function ‘int main()’: user.cpp:121:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < g[x].size(); ++i) ^