Compilare: user.cpp: In function ‘int main()’: user.cpp:59:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("hacker.in", "r", stdin); ^ user.cpp:60:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("hacker.out", "w", stdout); ^ user.cpp:64:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d\n", &N, &K); ^ user.cpp:65:18: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%s", sir); ^ user.cpp: In function ‘int solve(std::__cxx11::string)’: user.cpp:53:35: warning: ‘curr’ may be used uninitialized in this function [-Wmaybe-uninitialized] if (N & 1) curr = (1LL * curr * K) % mod; ^