当使用std::map您需要有序的数据。 您必须(按顺序)打印/访问数据。 您需要元素的前身/继承者。// CPP program to demonstrate use of std::map #include <bits/stdc++.h> int main() { // Ordered map std::map<int, int> order; // Mapping values to keys order[5] = 10; order[3] = 5; ...
Ordered map vs. Unordered map – A Performance StudyThere comes a time in most complex programs where you want to ask a simple question like, ‘have I already processed a string with this id’? Linear searches through an array are easy to write and work well enough for small array sizes...
I submitted this solution using map which took 61ms to pass:70273184. Today, just out of curiosity, I thought of submitting the same solution using unordered map, which I later found out doesn't have a hash function for pairs, so I copied the hash function fromGeeksForGeeks...
I submitted this solution using map which took 61ms to pass:70273184. Today, I thought of submitting the same solution using unordered map, which I later found out doesn't have a hash function for pairs, so I copied the hash function fromGeeksForGeeksand then submitted the ...
unordered_map:哈希表(杂乱但高效的仓库) unordered_map内部是用哈希表实现的。 继续用图书馆打比方: 这是一个特殊的图书馆,没有明显的排序 但图书管理员有一个神奇的公式,输入书名就能直接告诉你书在哪个架子上 你直接去那个架子就能找到书,不需要一步步查找 ...
// CPP program to demonstrate use of std::map #include <bits/stdc++.h> int main() { // Ordered map std::map<int, int> order; // Mapping values to keys order[5] = 10; order[3] = 5; order[20] = 100; order[1] = 1; // Iterating the map and // printing ordered values...
👉c++ - Is there any advantage of using map over unordered_map in case of trivial keys? - Stack Overflow Don't forget that keeps its elements ordered. If you can't give that up, obviously you can't use .mapunordered_map Something else to keep in mind is that generally uses more me...
unordered_map ClassArticle 06/21/2022 9 contributors Feedback In this article Syntax Members Remarks Requirements Show 48 more The class template describes an object that controls a varying-length sequence of elements of type std::pair<const Key, Ty>. The sequence is weakly ordered by a...
The arguments forwarded to construct an element to be inserted into the unordered_map unless it already contains an element whose value is equivalently ordered. Return Value A pair whose bool component returns true if an insertion was made and false if the unordered_map already contained an elemen...
set<int> orderedSet; // 使用 std::unordered_set 存储不重复的元素,元素是无序的 unordered_set<int> unorderedSet; // 插入元素 orderedSet.insert(3); orderedSet.insert(1); orderedSet.insert(4); orderedSet.insert(2); unorderedSet.insert(3); ...