Compilare: main.cpp: In function 'void dfs(int)': main.cpp:29:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i<v[na].size(); i++) ~^~~~~~~~~~~~~ main.cpp: In function 'bool bf(int)': main.cpp:59:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i<v[na].size(); i++) ~^~~~~~~~~~~~~