Compilare: user.cpp: In function ‘void check_square(long long unsigned int)’: user.cpp:74:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (1LL * (rad + 1) * (rad + 1) == A) ^ user.cpp:77:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (1LL * rad * rad != A) ^ user.cpp: In function ‘int main()’: user.cpp:91:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ubercool.in","r",stdin); ^ user.cpp:92:43: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ubercool.out","w",stdout); ^ user.cpp:94:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:102:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%llu", &X); ^