【C++/STL】map和set介绍

#include<iostream>
#include<set>
#include<map>
#include<vector>

using namespace std;

void test_set1()
{
	//主要功能：key模型搜索
	//次要功能：排序+去重
	set<int> s1;
	s1.insert(1);
	s1.insert(11);
	s1.insert(3);
	s1.insert(1);
	s1.insert(4);
	s1.insert(2);
	set<int>::iterator it = s1.begin();
	while (it != s1.end())
	{
		cout << *it << " ";
		++it;
	}
	cout << endl;

	vector<int> v = { 3,2,8,1,10,2 };
	set<int> s2(v.begin(), v.end());
	for (auto e : s2)
	{
		cout << e << " ";
	}
	cout << endl;

	set<int>s3 = { 3,2,8,1,10,2 };
	for (auto e : s3)
	{
		cout << e << " ";
	}
	cout << endl;
	s3.erase(8);
	s3.erase(18);
	for (auto e : s3)
	{
		cout << e << " ";
	}
	cout << endl;

	auto pos = s3.find(10);
	if (pos != s3.end())
	{
		cout << *pos << endl;
		s3.erase(pos);
	}
	else
	{
		cout << "找不到" << endl;
	}
	for (auto e : s3)
	{
		cout << e << " ";
	}
	cout << endl;

}

void test_set2()
{
	set<int> myset;
	for (int i = 1; i < 10; i++) 
		myset.insert(i * 10); // 10 20 30 40 50 60 70 80 90

	for (auto e : myset)
	{
		cout << e << " ";
	}
	cout << endl;
	//[30,70)
	auto itlow = myset.lower_bound(30);         //   >=   
	auto itup = myset.upper_bound(60);          //   >              

	myset.erase(itlow, itup);           // 10 20 70 80 90

	for (auto e : myset)
	{
		cout << e << " ";
	}
	cout << endl;
}

void test_set3()
{
	//主要功能：key模型搜索
	//次要功能：排序 不去重
	multiset<int> s1;
	s1.insert(1);
	s1.insert(2);
	s1.insert(11);
	s1.insert(3);
	s1.insert(1);
	s1.insert(4);
	s1.insert(2);
	multiset<int>::iterator it = s1.begin();
	while (it != s1.end())
	{
		cout << *it << " ";
		++it;
	}
	cout << endl;

	auto pos = s1.find(2);
	while (pos != s1.end()&&*pos==2)
	{
		cout << *pos << " ";
		++pos;
	}
}

void test_map1()
{
	map<string, string> dict;
	pair<string, string> kv1("sort", "排序");
	dict.insert(kv1);
	dict.insert(pair<string, string>("left", "左边"));
	dict.insert(make_pair("right", "右边"));

	// 隐式类型转换
	//单参数和多参数都支持隐式类型转换
	//如果是多参数，用花括号括起来即可
	pair<string, string> kv2 = { "string","字符串" };
	dict.insert({ "string","字符串" });

	map<string, string> dict2 = { {"left", "左边"},{"right", "右边"} };

	map<string, string>::iterator it = dict.begin();
	while (it != dict.end())
	{
		//cout << *it << " ";  //错误
		cout << (*it).first << ":" << (*it).second << endl;
		cout << it->first << ":" << it->second << endl;
		cout << it.operator->()->first << ":" << it.operator->()->second << endl;

		++it; 
	}
	cout << endl;

	for (auto& kv : dict)
	{
		cout << kv.first << ":" << kv.second << endl;
	}
	cout << endl;
}

void test_map2()
{
	string arr[] = { "苹果","西瓜","苹果","西瓜","苹果","苹果","西瓜","苹果","香蕉",
	"苹果","香蕉","苹果","草莓","苹果","草莓" };
	map<string, int> countMap;
	for (auto& e : arr)
	{
		countMap[e]++; 
		/*auto it = countMap.find(e);
		if (it != countMap.end())
		{
			it->second++;
		}
		else
		{
			countMap.insert({ e,1 });
		}*/
	}
	for (auto& kv : countMap)
	{
		cout << kv.first << ":" << kv.second << endl;
	}
	cout << endl;
	 
	multimap<int, string> sortMap;
	for (auto& kv : countMap)
	{
		//sortMap[kv.second] = kv.first;
		sortMap.insert({ kv.second,kv.first });
	}
	cout << endl;

	for (auto& kv : sortMap)
	{
		cout << kv.first << ":" << kv.second << endl;
	}
	cout << endl;
}

void test_map3()
{
	map<string, string> dict;
	dict.insert({ "string","字符串" });

	//插入（一般不这么用）
	dict["right"];

	//插入+修改
	dict["left"] = "左边";
	
	//"查找"
	cout << dict["string"] << endl;

	//修改
	dict["right"] = "右边";

	string str;
	cin >> str;
	if (dict.count(str))
	{
		cout << "在" << endl;
	}
	else
	{
		cout << "不在" << endl;
	}
}

int main()
{
	test_map3();
	return 0;
}