Compilare: user.cpp: In function ‘int main()’: user.cpp:36:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("metrou5.in" , "r", stdin); ^ user.cpp:37:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("metrou5.out" , "w", stdout); ^ user.cpp:38:29: 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:44:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i]); ^ user.cpp: In function ‘void precalc()’: user.cpp:25:51: warning: iteration 150004u invokes undefined behavior [-Waggressive-loop-optimizations] fact[i] = fact[i - 1] * i , fact[i] %= MOD; ^ user.cpp:23:5: note: containing loop for (int i = 1; i<=200000; ++i) ^