Compilare: user.cpp: In function ‘int main()’: user.cpp:29:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<v[o].size(); ++i) ^ user.cpp:51:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0; i<v[I].size(); ++i) ^ user.cpp:12:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("tric.in", "r", stdin); ^ user.cpp:13:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("tric.out", "w", stdout); ^ user.cpp:15:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &n, &m); ^ user.cpp:19:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &x, &y); ^