Compilare: main.cpp: In function 'void get_first(node*&, node*&)': main.cpp:54:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<huffman_tree.size(); i++) ~^~~~~~~~~~~~~~~~~~~~ main.cpp:67:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<huffman_tree.size(); i++) ~^~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'void prt_huffman()': main.cpp:84:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<huffman_tree.size(); i++) ~^~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'void get_first(node*&, node*&)': main.cpp:53:9: warning: 'index' may be used uninitialized in this function [-Wmaybe-uninitialized] int index; ^~~~~