std::map 是一种有序关联容器,它包含具有唯一键的键值对。键之间以比较函数 Compare 排序。搜索、移除和插入操作拥有对数复杂度。map 通常实现为红黑树。 std::map 的迭代器以升序迭代各键,此升序由构造时所用的比较函数定义。就是说,给定 m,一个 std::map it_l 和it_r,m 的可解引用迭代器
>usingmap=std::map<Key, T, Compare, std::pmr::polymorphic_allocator<std::pair<constKey, T>>>; } (2)(since C++17) std::mapis a sorted associative container that contains key-value pairs with unique keys. Keys are sorted by using the comparison functionCompare. Search, removal, and in...
std::map iterator find(constKey&key); (1)(constexpr since C++26) const_iterator find(constKey&key)const; (2)(constexpr since C++26) template<classK> iterator find(constK&x); (3)(since C++14) (constexpr since C++26) template<classK> ...
#include <iostream> #include <map> void println(auto rem, const auto& container) { std::cout << rem << '{'; for (char sep[]{0, ' ', 0}; const auto& [key, value] : container) std::cout << sep << '{' << key << ", " << value << '}', *sep = ','; std::cou...
indenter _ind;doIndent();fprintf(stderr,"log...\n");for(...)dfs(...); } #基于范围的 for 循环 示例: vector <int> vec;for(...) vec.push_back(...);for(autoit: vec) {...} #lambda 表达式 推荐找点实例来看,在一定程度上能简化代码。注意效率可能较低 ...
External Links−Non-ANSI/ISO Libraries−Index−std Symbol Index C reference C89,C95,C99,C11,C17,C23│Compiler supportC99,C23 Language Basic concepts Keywords Preprocessor Expressions Declaration Initialization Functions Statements Headers Type support ...
External Links−Non-ANSI/ISO Libraries−Index−std Symbol Index C reference C89,C95,C99,C11,C17,C23│Compiler supportC99,C23 Language Basic concepts Keywords Preprocessor Expressions Declaration Initialization Functions Statements Headers Type support ...
External Links−Non-ANSI/ISO Libraries−Index−std Symbol Index C reference C89,C95,C99,C11,C17,C23│Compiler supportC99,C23 Language Basic concepts Keywords Preprocessor Expressions Declaration Initialization Functions Statements Headers Type support ...
; std::hash<std::string> hash_fn; size_t str_hash = hash_fn(str); std::cout << str_hash << '\n'; } Output: 391070135 Veranschaulicht Schaffung einer Hash-Funktion für einen Benutzer definierten Typ. Mit diesem als Template-Parameter für std::unordered_map, std::unordered_set...
std::is_default_constructible<std::hash<Key>>::value std::is_copy_constructible<std::hash<Key>>::value std::is_move_constructible<std::hash<Key>>::value std::is_copy_assignable<std::hash<Key>>::value std::is_move_assignable<std::hash<Key>>::value In other words, they exi...