Compilare: user.cpp: In function ‘void solve()’: user.cpp:45:43: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %lld", &a, &b, &c, &n); ^ user.cpp: In function ‘int main()’: user.cpp:76:37: 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:77:39: 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:80:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ", &t); ^