Compilare: user.cpp: In function ‘int main()’: user.cpp:61:34: 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:62:36: 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:66:26: 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:67:18: 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:54:22: warning: ‘curr’ may be used uninitialized in this function [-Wmaybe-uninitialized] curr = (curr * K) % mod; ^