Compilare: user.cpp: In function ‘void bfs()’: user.cpp:14:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<s[a].size(); i++) ^ user.cpp:10:9: warning: unused variable ‘b’ [-Wunused-variable] int a,b,i; ^ user.cpp: In function ‘int main()’: user.cpp:28:17: warning: unused variable ‘max’ [-Wunused-variable] int n,m,i,a,b,max=0; ^ user.cpp:26:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.in","r",stdin); ^ user.cpp:27:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sortaret.out","w",stdout); ^ user.cpp:29:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:32:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^