Compilare: user.cpp: In function ‘void df1(int)’: user.cpp:11:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i<g[x].size(); ++i) ^ user.cpp: In function ‘void df2(int, bool)’: user.cpp:22:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i<gt[x].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:28:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.in","r",stdin); ^ user.cpp:29:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.out","w",stdout); ^ user.cpp:30:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n,&m); ^ user.cpp:33:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x,&y); ^