Compilare: user.cpp: In function ‘int main()’: user.cpp:86:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(neigh[i].size() < k) { ^ user.cpp:95:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<neigh[src].size();i++){ ^ user.cpp:63:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zone2.in","r",stdin); ^ user.cpp:64:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zone2.out","w",stdout); ^ user.cpp:66:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld %ld",&n,&m,&k); ^ user.cpp:67:41: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=1;i<=n;i++) scanf("%s",a[i]+1); ^