Compilare: user.cpp: In function ‘void df(int)’: user.cpp:14:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < g[x].size() ; ++i) ^ user.cpp: In function ‘void tdf(int)’: user.cpp:29:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < t[x].size() ; ++i) ^ user.cpp: In function ‘int main()’: user.cpp:41:32: 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:42:34: 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:46:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &n); ^ user.cpp:47:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &m); ^ user.cpp:51:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &x); ^ user.cpp:52:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d" , &y); ^