Compilare: user.cpp: In function ‘void BFS(int)’: user.cpp:23:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < A[S[i]].size(); j++) ^ user.cpp: In function ‘int main()’: user.cpp:49:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("statiuni.in", "r", stdin); ^ user.cpp:50:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("statiuni.out", "w", stdout); ^ user.cpp:52:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d ", &N,&k); ^ user.cpp:55:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d ", &x, &y); ^