Compilare: user.cpp: In function ‘void euler(int)’: user.cpp:22:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < e[x].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:56:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < sol.size() - 1; i++) ^ user.cpp:45:15: warning: variable ‘b’ set but not used [-Wunused-but-set-variable] int a =0, b =0; ^