Compilare: user.cpp: In function ‘void bfs(int)’: user.cpp:21:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0 ; i < v[k].size() ; i++){ ^ user.cpp: In function ‘int main()’: user.cpp:38:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sate.in","r",stdin); ^ user.cpp:39:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sate.out","w",stdout); ^ user.cpp:41:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d",&n,&m,&x1,&y1); ^ user.cpp:46:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&x,&y,&c); ^