Compilare: user.cpp: In function ‘void BFS(int, int*)’: user.cpp:33:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0;i < G[Node].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:79:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0;i < Sol.size();i++) ^ user.cpp:48:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("graf.in","r",stdin); ^ user.cpp:49:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("graf.out","w",stdout); ^ user.cpp:51:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d",&N,&M,&X,&Y); ^ user.cpp:57:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&A,&B); ^