Compilare: user.cpp: In function ‘int main()’: user.cpp:106:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("abcacm.in", "r", stdin); ^ user.cpp:107:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("abcacm.out", "w", stdout); ^ user.cpp:109:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%llu", &t); ^ user.cpp:111:47: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%llu %llu %llu %llu", &a, &b, &c, &i); ^