Compilare: main.cpp: In function 'void dfs(int)': main.cpp:18:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<adj[nod].size();i++){ ~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:26:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dfs.in", "r", stdin); ^ main.cpp:27:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dfs.out", "w", stdout); ^