Compilare: main.cpp: In function 'void dfs(int)': main.cpp:99:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i <= g[u].size(); ++i) ~~^~~~~~~~~~~~~~ main.cpp:104:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int v, ptr = 0; ptr < g[u].size(); ++ptr) { ~~~~^~~~~~~~~~~~~ main.cpp:115:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i <= g[u].size(); ++i) ~~^~~~~~~~~~~~~~