Compilare: main.cpp: In function 'int main()': main.cpp:63:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<codes[t].size(); i++) ~^~~~~~~~~~~~~~~~ main.cpp:59:39: warning: 'root' may be used uninitialized in this function [-Wmaybe-uninitialized] dfs (children, codes[t], root); ^