Compilare: main.cpp: In member function 'void HuffmanCoding::buildTree(const std::vector<int>&)': main.cpp:81:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<tree.size(); ++i) ~^~~~~~~~~~~~ main.cpp:85:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<tree.size(); ++i) ~^~~~~~~~~~~~ main.cpp: In function 'void solveInput()': main.cpp:144:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0; i<huffman.tree.size(); ++i) ~^~~~~~~~~~~~~~~~~~~~