Compilare: user.cpp: In function ‘void bfs(int)’: user.cpp:25:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<lista[nod].size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:67:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<sol.size();++i) ^ user.cpp:39:33: 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:40:35: 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:42:34: 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:46:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^