Compilare: user.cpp: In function ‘void bfs(int)’: user.cpp:18:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<graf[St.front()].size();i++) ^ user.cpp: In function ‘void bfs1(int)’: user.cpp:39:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<graf[St.front()].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:54:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("graf.in","r",stdin); ^ user.cpp:55:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("graf.out","w",stdout); ^ user.cpp:56:33: 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); ^ user.cpp:59:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&X,&Y); ^