Compilare: user.cpp: In function ‘int main()’: user.cpp:84:37: 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:85:39: 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:87:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n%s", &n, &k, s); ^