Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:11:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0 ; i < g[nod].size() ; i ++) ^ user.cpp: In function ‘int main()’: user.cpp:17:36: 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); ^ user.cpp:18:38: 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); ^ user.cpp:20:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d" , &n , &m); ^ user.cpp:23:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d" , &u , &v); ^