Compilare: user.cpp: In function ‘int main()’: user.cpp:5:55: warning: unused variable ‘i’ [-Wunused-variable] long long x11,x12,x21,x22,y11=0,y12=0,y21=0,y22=0,i,n; ^ user.cpp:7:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("kfib.in","r",stdin); ^ user.cpp:8:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("kfib.out","w",stdout); ^ user.cpp:9:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld",&n); ^