Compilare: user.cpp: In function ‘void BFS(int)’: user.cpp:40:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < a[k].size(); ++i) ^ user.cpp: In function ‘void Read(int&)’: user.cpp:23:49: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++poz==DIM) fread(buff,1,DIM,stdin),poz=0; ^ user.cpp:27:53: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] if(++poz==DIM) fread(buff,1,DIM,stdin),poz=0; ^ user.cpp: In function ‘int main()’: user.cpp:53:33: 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:54:35: 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:58:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d",&N,&M,&X,&Y); ^