Compilare: user.cpp: In function ‘int main()’: user.cpp:33:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("criza.in","r",stdin); ^ user.cpp:34:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("criza.out","w",stdout); ^ user.cpp:35:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n);st=1; ^ user.cpp:37:49: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld",&y[i],&x[i]),dr=max(dr,x[i]); ^