Compilare: user.cpp: In member function ‘Hg Hg::operator+=(const Hg&)’: user.cpp:49:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:52:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] {freopen("perm6.in","r",stdin);freopen("perm6.out","w",stdout);int n,k,i,j;scanf("%d%d",&n,&k);for(i=1;i<=n;i++)dp[i][0]=1; ^ user.cpp:52:63: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] {freopen("perm6.in","r",stdin);freopen("perm6.out","w",stdout);int n,k,i,j;scanf("%d%d",&n,&k);for(i=1;i<=n;i++)dp[i][0]=1; ^ user.cpp:52:95: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] {freopen("perm6.in","r",stdin);freopen("perm6.out","w",stdout);int n,k,i,j;scanf("%d%d",&n,&k);for(i=1;i<=n;i++)dp[i][0]=1; ^