Compilare: user.cpp: In function ‘int main()’: user.cpp:93:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<sol.size(); ++i) { ^ user.cpp:97:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<sol.size(); ++i) cout<<sol[i]<<' '; ^ user.cpp:68:11: warning: ‘b’ may be used uninitialized in this function [-Wmaybe-uninitialized] int b; ^