Compilare: user.cpp: In function ‘int main()’: user.cpp:8:13: warning: unused variable ‘j’ [-Wunused-variable] int n,i,j,t,mn,mx,x; ^ user.cpp:6:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dif2.in","r",stdin); ^ user.cpp:7:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dif2.out","w",stdout); ^ user.cpp:9:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&t,&n); ^ user.cpp:14:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^ user.cpp:18:29: warning: ‘mx’ may be used uninitialized in this function [-Wmaybe-uninitialized] printf("%lld",1LL*mx*mx-1LL*mn*mn); ^ user.cpp:18:39: warning: ‘mn’ may be used uninitialized in this function [-Wmaybe-uninitialized] printf("%lld",1LL*mx*mx-1LL*mn*mn); ^