Compilare: user.cpp: In function ‘void BFS(int)’: user.cpp:22:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i < v[x].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:60:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (t<v[j].size()) ^ user.cpp:40:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("permlcs.in","r",stdin); ^ user.cpp:41:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("permlcs.out","w",stdout); ^ user.cpp:42:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:43:42: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=1; i<=n; i++) scanf("%d",&a[i]); ^ user.cpp:53:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^