Compilare: main.cpp: In instantiation of 'void segment_tree<type, val_type, return_type, LazyType, update_policy, query_policy, lazy_policy>::create(const std::vector<type>&) [with type = int; val_type = int; return_type = int; LazyType = int; update_policy = update_policy; query_policy = query_policy; lazy_policy = lazy_policy]': main.cpp:215:24: required from here main.cpp:28:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < vec.size() * 4; ++i) ~~^~~~~~~~~~~~~~~~ main.cpp:33:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < vec.size(); ++i) main.cpp: In instantiation of 'void segment_tree<type, val_type, return_type, LazyType, update_policy, query_policy, lazy_policy>::update(int, int, val_type, int, int, int) [with type = int; val_type = int; return_type = int; LazyType = int; update_policy = update_policy; query_policy = query_policy; lazy_policy = lazy_policy]': main.cpp:229:36: required from here main.cpp:74:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(k*4 < data.size() && k*4+1 < data.size()) main.cpp:74:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(k*4 < data.size() && k*4+1 < data.size()) main.cpp:83:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (k * 4 + 2 < data.size() && k * 4 + 3 < data.size()) main.cpp:83:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (k * 4 + 2 < data.size() && k * 4 + 3 < data.size()) main.cpp: In function 'int main()': main.cpp:196:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arbint.in", "r", stdin); ^ main.cpp:197:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arbint.out", "w", stdout); ^