Compilare: user.cpp: In function ‘int main()’: user.cpp:78:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (v.size() > k) ^ user.cpp:83:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (v.size() == k) ^ user.cpp:87:40: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v.size(); ++i) ^ user.cpp:56:13: warning: unused variable ‘ind’ [-Wunused-variable] int ind = 0; ^ user.cpp:21:37: 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:22:39: 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:26:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &n, &k); ^