是的,C++中的unordered_map是标准库中的一种关联容器,用于存储键值对,并且不按照特定顺序进行排序。unordered_map可以用来快速查找和插入键值对,而且具有常数时间的复杂度。因此,unordered_map是C++中非常常用的数据结构之一。 0 赞 0 踩最新问答linux vconfig如何添加vlan linux vconfig命令作用是什么 linux userdel...
#include<iostream>#include<unordered_map>usingnamespacestd;intmain(void){unordered_map<char,int>um={{'a',1},{'b',2},{'c',3},};um.insert(pair<char,int>('d',4));um.insert(pair<char,int>('e',5));cout<<"Unordered map contains following elements"<<endl;for(autoit=um.begin();...
"red"}, {"lemon","yellow"} };// 直接在定义后赋值unordered_map<string, string>p3(p2);// 拷贝p2给p3unordered_map<string, string>p4(p3.begin(), p3.end());// 通过迭代器一一赋值unordered_map<string, string> p5 = p4;// 通过赋值符号直接拷贝unordered_map<string, string> p6 =...
containsC++20 Compruebe si hay un elemento con la clave especificada en unordered_map. emplace Agrega un elemento construido en contexto. emplace_hint Agrega un elemento construido en contexto, con sugerencia. empty Comprueba si no hay ningún elemento presente. end Designa el final de la secu...
Run this code #include <iostream>#include <unordered_map>intmain(){std::unordered_map<int,char>example{{1,'a'},{2,'b'}};for(intx:{2,5})if(example.contains(x))std::cout<<x<<": Found\n";elsestd::cout<<x<<": Not found\n";} ...
unordered_map和map类似,都是存储的key-value的值,可以通过key快速索引到value。不同的是unordered_map不会根据key的大小进行排序, 存储时是根据key的hash值判断元素是否相同,即unordered_map内部元素是无序的,而map中的元素是按照二叉搜索树存储,进行中序遍历会得到有序遍历。
unordered_map::count unordered_map::find unordered_map::contains (C++20) unordered_map::equal_range Bucket interface unordered_map::begin(size_type)unordered_map::cbegin(size_type) unordered_map::end(size_type)unordered_map::cend(size_type) ...
#include <iostream>#include <unordered_map>intmain(){std::unordered_map<int,char>example={{1,'a'},{2,'b'}};if(example.contains(2)){std::cout<<"Found\n";}else{std::cout<<"Not found\n";}} 输出: Found 参阅 find 寻找带有特定键的元素 ...
containsC++20 Check if there's an element with the specified key in the unordered_map. emplace Adds an element constructed in place. emplace_hint Adds an element constructed in place, with hint. empty Tests whether no elements are present. end Designates the end of the controlled sequence. eq...
containsC++20 Check if there's an element with the specified key in the unordered_map. emplace Adds an element constructed in place. emplace_hint Adds an element constructed in place, with hint. empty Tests whether no elements are present. end Designates the end of the controlled sequence. eq...