Compilare: user.cpp: In function ‘void solve()’: user.cpp:40:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<q.size(); i++) ^ user.cpp:42:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j=0; j<a[q[i]].size(); j++) ^ user.cpp: At global scope: user.cpp:59:6: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] main() ^