Compilare: main.cpp: In function 'void first_DFS(int)': main.cpp:20:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < ad[node].size(); i++) ~~^~~~~~~~~~~~~~~~~ main.cpp: In function 'void second_DFS(int)': main.cpp:33:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < ad[node].size(); i++) ~~^~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:63:21: warning: 'node' may be used uninitialized in this function [-Wmaybe-uninitialized] second_DFS(node); ^