C++ 关联容器使用 map, unordered_map, set, unordered_set, multiset, unordered_multiset

#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <iostream>
#include <array>

using namespace std;

template <typename AssozCont>
bool containsElement5(const AssozCont& assozCont) {
	return assozCont.contains(5);
}

int main() {

	// std::map
	std::map<std::string, int> m{ {"Dijkstra", 1972}, {"Scott", 1976} };
	m["Ritchie"] = 1983;
	std::cout << m["Ritchie"]; // 1983
	for (auto p : m) std::cout << "{" << p.first << "," << p.second << "}";
	// {Dijkstra,1972},{Ritchie,1983},{Scott,1976}
	m.erase("Scott");
	for (auto p : m) std::cout << "{" << p.first << "," << p.second << "}";
	// {Dijkstra,1972},{Ritchie,1983}
	m.clear();
	std::cout << m.size() << std::endl; // 0



	// std::unordered_map
	std::unordered_map<std::string, int> um{ {"Dijkstra", 1972}, {"Scott", 1976} };
	um["Ritchie"] = 1983;
	std::cout << um["Ritchie"]; // 1983
	for (auto p : um) std::cout << "{" << p.first << "," << p.second << "}";
	// {Ritchie,1983},{Scott,1976},{Dijkstra,1972}
	um.erase("Scott");
	for (auto p : um) std::cout << "{" << p.first << "," << p.second << "}";
	// {Ritchie,1983},{Dijkstra,1972}
	um.clear();
	std::cout << um.size() << std::endl; // 0

	// std::set
	std::set<int> mySet{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
	std::cout << "containsElement5(mySet): "
		<< containsElement5(mySet); // true


	//std::unordered_set
	std::unordered_set<int> myUnordSet{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
	std::cout << "containsElement5(myUnordSet): "
		<< containsElement5(myUnordSet); // true


	// std::multiset
	std::multiset<int> myMuliSet{ 3, 1, 5, 3, 4, 5, 1, 4, 4, 3, 2, 2, 7, 6, 4, 3, 6 };
	for (auto s : myMuliSet) std::cout << s << " ";
	// 1 1 2 2 3 3 3 3 4 4 4 4 5 5 6 6 7
	myMuliSet.insert(8);
	std::array<int, 5> myArr{ 10, 11, 12, 13, 14 };
	myMuliSet.insert(myArr.begin(), myArr.begin() + 3);
	myMuliSet.insert({ 22, 21, 20 });
	for (auto s : myMuliSet) std::cout << s << " ";
	// 1 1 2 2 3 3 3 3 4 4 4 4 5 5 6 6 7 10 11 12 20 21 22
	std::cout << myMuliSet.erase(4); // 4
	myMuliSet.erase(myMuliSet.lower_bound(5), myMuliSet.upper_bound(15));
	for (auto s : myMuliSet) std::cout << s << " ";
	// 1 1 2 2 3 3 3 3 20 21 22

	// std::multimap
	std::multimap<char, int> multiMap = { {'a', 10}, {'a', 20}, {'b', 30} };
	for (auto p : multiMap) std::cout << "{" << p.first << "," << p.second << "} ";
	// {a,10} {a,20} {b,30}

	return 0;

}