Compilare: user.cpp: In function ‘int main()’: user.cpp:27:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[q[0]].size();i++) ^ user.cpp:14:19: warning: unused variable ‘j’ [-Wunused-variable] int n,m,x,y,i,j,s; ^ user.cpp:12:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bfs.in","r",stdin); ^ user.cpp:13:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bfs.out","w",stdout); ^ user.cpp:15:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&m,&s); ^ user.cpp:18:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^