Compilare: user.cpp: In function ‘bool ok(int)’: user.cpp:92:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] return (curr_ans.size() <= K); ^ user.cpp: In function ‘int main()’: user.cpp:97:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("salvare.in", "r", stdin); ^ user.cpp:98:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("salvare.out", "w", stdout); ^ user.cpp:100:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d", &arb.N, &K); ^ user.cpp:104:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d %d", &x, &y); ^