Compilare: user.cpp: In function ‘int get(std::vector<int>*, int)’: user.cpp:35:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (l - pos < v->size()) ^ user.cpp: In function ‘void add_to_vector(std::vector<int>*, int)’: user.cpp:42:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (l - pos < v->size()) { ^ user.cpp:50:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (l - pos == v->size()) { ^ user.cpp: In function ‘void dfs(int)’: user.cpp:90:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < down[to]->size(); i++) ^ user.cpp: In function ‘void solve_bucket(int)’: user.cpp:123:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (down[1]->size() == l) ^ user.cpp: In function ‘int main()’: user.cpp:133:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("meow.in", "r", stdin); ^ user.cpp:134:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("meow.out", "w", stdout); ^