Compilare: user.cpp: In function ‘void _back(int, int)’: user.cpp:47:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pas == cic.size()) { ^ user.cpp: In function ‘int main()’: user.cpp:66:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("spirala2.in","r",stdin); ^ user.cpp:67:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("spirala2.out","w",stdout); ^ user.cpp:69:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^