Compilare: user.cpp: In function ‘int main()’: user.cpp:12:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("doi.in", "r", stdin); ^ user.cpp:13:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("doi.out", "w", stdout); ^ user.cpp:17:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(scanf("%d", &T); T; -- T) { ^ user.cpp:18:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^