Compilare: user.cpp: In function ‘int main()’: user.cpp:35:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("xor.in","r",stdin); ^ user.cpp:36:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("xor.out","w",stdout); ^ user.cpp:38:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (scanf("%d%lld", &t, &p); t > 0; t--) { ^ user.cpp:39:54: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld%lld%lld", &l1, &c1, &l2, &c2); ^