#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<<": 找到\n";elsestd::cout<<x<<": 未找到\n";} 输出:
在C++ 中,<unordered_map>是标准模板库(STL)的一部分,提供了一种基于哈希表的键值对容器。 与std::map不同,unordered_map不保证元素的排序,但通常提供更快的查找速度。 unordered_map是一个关联容器,它存储了键值对(key-value pairs),其中每个键(key)都是唯一的。unordered_map使用哈希表来存储元素,这使得它在...
unordered_map::reserve Observers unordered_map::hash_function unordered_map::key_eq Non-member functions operator==operator!= (C++11)(C++11)(until C++20) std::swap(std::unordered_map) (C++11) erase_if(std::unordered_map) (C++20)
Likewise, any associative key-value containers (std::map, std::multimap, std::unordered_map, std::unordered_multimap) whose keys can construct an std::string and whose values can be used to construct JSON values (see examples above) can be used to create a JSON object. Note that in case...
unordered_map<int,char>example{{1,'a'},{2,'b'}};if(autosearch=example.find(2);search!=example.end())std::cout<<"Found "<<search->first<<' '<<search->second<<'\n';elsestd::cout<<"Not found\n";// C++20 demo: Heterogeneous lookup for unordered containers (transparent hashing)...
Security Find and fix vulnerabilities Actions Automate any workflow Codespaces Instant dev environments Issues Plan and track work Code Review Manage code changes Discussions Collaborate outside of code Code Search Find more, search less Explore
unordered_map(C++11) unordered_multimap(C++11) unordered_set(C++11) unordered_multiset(C++11) Container adaptors span(C++20)−mdspan(C++23) Iterators library Ranges library(C++20) Range factories−Range adaptors generator(C++23) Algorithms library ...
<unordered_set> #include <Common/Jemalloc.h> #include "config.h" #include <Common/config_version.h> #if defined(OS_LINUX) # include <cstdlib> # include <sys/un.h> # include <sys/mman.h> # include <sys/ptrace.h> # include <Common/hasLinuxCapability.h> #endif #if USE_SSL # ...
参考网站 https://www.runoob.com/cplusplus/cpp-libs-unordered_map.html强烈推荐:https://www.cnblogs.com/langyao/p/8823092.html#include <unordered_map>在C++ 中,<unordered_map> 是标准模板库(STL)的一部分,提供了一种基于哈希表的键值对容器。 与std::map 不同,unordered_map 不保证元素的排序,但...
map is faster in cpp than unordered_map? So today I was up solvingCodeforces Round #790 (Div. 4)i got stuck in problemFbc i was usingunordered_mapand repetedly getting tle at 19th and 20th testcase i gave up and tried to look into solution i found out they were usingmapi tried it...