Compilare: user.cpp: In function ‘int BF()’: user.cpp:7:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] #define sz size() ^ user.cpp:32:32: note: in expansion of macro ‘sz’ for (j = 0; j < G[nod].sz; j++) ^ user.cpp: In function ‘int main()’: user.cpp:7:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] #define sz size() ^ user.cpp:63:30: note: in expansion of macro ‘sz’ for (i = 0; i < G[N].sz; i++) ^ user.cpp:47:46: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("symmetricgraph2.in", "r", stdin); ^ user.cpp:48:48: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("symmetricgraph2.out", "w", stdout); ^ user.cpp:52:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d ", &N, &M); ^ user.cpp:56:39: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d ", &x, &y, &z); ^