Compilare: user.cpp: In function ‘int main()’: user.cpp:20:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (tree.size() > K) ^ user.cpp:22:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (tree.size() == K && ( maxIndex == -1 || *tree.begin() > maximum)) ^ user.cpp:27:63: warning: ‘maximum’ may be used uninitialized in this function [-Wmaybe-uninitialized] g << maxIndex + 1 << " " << maxIndex + K << " " << maximum; ^