std::unordered_setis an associative container that contains a set of unique objects of typeKey. Search, insertion, and removal have average constant-time complexity. Internally, the elements are not sorted in any particular order, but organized into buckets. Which bucket an element is placed into...
Internally, the elements in the unordered_set are not sorted in any particular order, but organized into buckets depending on their hash values to allow for fast access to individual elements directly by their values (with a constant average time complexity on average). unordered_set containers ar...
Complexity 1-5) Constant. 6-8) Average case linear (i.e. O(N), where N is std::distance(first, last)), worst case quadratic, i.e. O(N2). 9,10) Linear in size of other. 11,12) Constant. If alloc is given and alloc != other.get_allocator(), then linear. 13-15) Average...
c++algorithmc++11data-structurestime-complexity 关注收藏 回复 阅读3 1 个回答 得票最新 社区维基发布于 8 分钟前✓ 已被采纳 它们几乎相同。 unordered_set 只包含键,没有值。没有从键到值的映射,因此不需要 operator[]。 unordered_map 将键映射到值。 您可以使用 --- 中的各种 find unordered_set 来...
Also wondering why the unordered_set is about 2'500 times slower for a find than a vector? I mean the worst case scenario for vector is supposed to be O(n), isn't unordered_set supposed to be better than that? I know that trying to predict what is the average complexity is usually...
Possible output: first: corn milk wood second: oil copper iron Complexity Constant. Iterator validity All iterators, pointers and references remain valid, but now are referring to elements in the other container, and iterate in it. See also swap (unordered_set) Exchanges contents of two unorder...
The best case and the average case complexity for all the operations in an unordered_map is O(1). While in the worst case, the time complexity for all the operations in an unordered_map is O(n). The difference between an unordered_map and an unordered_set is that an unordered_map sto...
unordered_map 将键映射到值。 您可以使用 --- 中的各种 find unordered_set 来定位事物。 原文由 1201ProgramAlarm 发布,翻译遵循 CC BY-SA 3.0 许可协议有用 回复 撰写回答 你尚未登录,登录后可以 和开发者交流问题的细节 关注并接收问题和回答的更新提醒 参与内容的编辑和改进,让解决方法与时俱进 注册...
Return value The number of buckets in the container. Complexity Constant. See also bucket_size returns the number of elements in specific bucket (public member function) max_bucket_count returns the maximum number of buckets (public member function)...
erase_if(std::unordered_set) (C++20) Deduction guides(C++17) Returns the average number of elements per bucket, that is,size()divided bybucket_count(). Parameters (none) Return value Average number of elements per bucket. Complexity Constant. See also...