Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:20:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<G[nod].size(); ++i) ^ user.cpp:43:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<G[nod].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:95:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] { freopen("arbore7.in", "r", stdin); ^ user.cpp:96:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arbore7.out", "w", stdout); ^ user.cpp:97:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:101:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^