Compilare: user.cpp: In function ‘int bfs()’: user.cpp:38:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[a].size();i++) { ^ user.cpp: In function ‘int main()’: user.cpp:58:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,a,b,r,e; ^ user.cpp:56:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("renovare.in","r",stdin); ^ user.cpp:57:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("renovare.out","w",stdout); ^ user.cpp:59:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&n,&m,&x); ^ user.cpp:62:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d",&a,&b,&r,&e); ^