Compilare: user.cpp: In function ‘int main()’: user.cpp:69:9: warning: unused variable ‘lim’ [-Wunused-variable] int lim=1<<n; ^ user.cpp:80:9: warning: unused variable ‘to’ [-Wunused-variable] int to=(1<<n)-1; ^ user.cpp:49:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hamilton.in","r",stdin); ^ user.cpp:50:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hamilton.out","w",stdout); ^ user.cpp:53:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&n,&m); ^ user.cpp:64:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&x,&y,&c); ^