Compilare: user.cpp: In function ‘int main()’: user.cpp:22:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i < R.size(); ++i ) ^ user.cpp: In function ‘void BFS()’: user.cpp:54:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int i = 0; i < V[nod].size(); ++i ) ^ user.cpp:59:48: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( int j = 0; j < V[x].size(); ++j ) ^ user.cpp: In function ‘void Input()’: user.cpp:28:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("markon.in","r",stdin); ^ user.cpp:29:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("markon.out","w",stdout); ^ user.cpp:31:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i%i",&N,&M,&x); ^ user.cpp:37:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i",&x); ^ user.cpp:42:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i",&x,&y); ^