Compilare: user.cpp: In function ‘void DFS(long int)’: user.cpp:27:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<list[nod].size();i++) DFS(nodes[i]); ^ user.cpp:29:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<nodes.size();j++){ ^ user.cpp: In function ‘int main()’: user.cpp:64:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("petsoft.in","r",stdin); ^ user.cpp:65:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("petsoft.out","w",stdout); ^ user.cpp:67:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld",&n); ^ user.cpp:69:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld",&nr); ^