C++-STL(6)-map-set -有序-增删改查

map<key,value> key 不同，value可同，有序。
set<key>            key不同 ，                       有序 。 用于整数去重排序最好不过了。不能改值。
代码亲测可行，自己MARK一下，也供大家参考。

map
 

void maptest()
{
	//1.定义 map<char, int> mymap;
	//2.插入insert pair<,>
	//3.得到大小 int nSize = mymap.size();
	//4.查找 iter=mymap.find()   输入key 返回iter
	//5.删除 int n=mymap.erase(key) 返1 成功；返0 不成功
	//6.删除全部 mymap.erase(mymap.begin(), mymap.end());
	//7.修改mymap['d']=4000;
	cout<<"map 增删改查 ******"<<endl;

	cout << "1定义 map<char, int> mymap;" << endl;
	cout << " 2插入insert pair<,>" << endl;
	map<char, int> mymap;
	mymap.insert(pair<char, int>('a', 100));
	mymap.insert(pair<char, int>('z', 200));
	mymap.insert(pair<char, int>('b', 300));
	mymap['d'] = 400;
	mymap.insert(map<char, int>::value_type('f', 500));
	map<char, int>::iterator iter;
	for (iter = mymap.begin(); iter != mymap.end(); iter++)
	{
		cout << iter->first << " " << iter->second << endl;
	}
	
	cout << " 3得到大小 int nSize = mymap.size();" << endl;
	int nSize = mymap.size();
	cout << nSize << endl;
	cout << "4.查找 iter=mymap.find(b)   输入key 返回iter" << endl;
	  iter = mymap.find('b');
	  cout << iter->first << " " << iter->second << endl;

	cout << "5.删除 int n=mymap.erase(key) 返1 成功；返0 不成功" << endl;
	int n = mymap.erase('b');
	cout << "删除后的返回值="<<n << endl;
	for (iter = mymap.begin(); iter != mymap.end(); iter++)
	{
		cout << iter->first << " " << iter->second << endl;
	}
	cout << "6.修改mymap['d']=4000;" << endl;
	mymap['d'] = 4000;
	cout << mymap['d'] << endl;

	cout << "7.删除全部 mymap.erase(mymap.begin(), mymap.end());" << endl;
	 mymap.erase(mymap.begin(), mymap.end());
	  nSize = mymap.size();
	 cout << "删除全部后map的长度"<<nSize << endl;

}

set
 

void settest()
{
	//1.定义 set<int> myset;
	//2.插入insert <key>
	//3.得到大小 int nSize = myset.size();
	//4.查找 iter=myset.find(key)   输入key 返回iter
	//5.定位 iter=lower_bound(key)  <=key 返回iter
	//  定位 iter = upper_bound(key) >=key 返回iter
	//6.删除 int n=myset.erase(key) 返1 成功；返0 不成功
	// 删除全部 mymap.clear();
	
	    cout << "1.定义 set<char, int> myset;" << endl;
		set<int> myset;
		myset.insert(1);
		myset.insert(2);
		myset.insert(10);
		myset.insert(100);
		myset.insert(4);
		myset.insert(8);
		myset.insert(9);
		cout << "2.插入insert <key>" << endl;
		set<int>::iterator iter;
		for (iter = myset.begin(); iter != myset.end(); iter++)
		{
			cout << *iter << endl;
		}
		cout << "auto 类型遍历" << endl;
		for (auto iter1 = myset.begin(); iter1 != myset.end(); iter1++)
		{
			cout << *iter1 << endl;
		}
			
		cout << "3.得到大小 int nSize = myset.size();" << myset.size() << endl;
		cout << "4.查找 iter=myset.find(key)   输入key 返回iter"   <<endl;
		      iter = myset.find(100);
		      cout << *iter << endl;

		cout << "5.定位 iter=lower_bound(key)  <=key 返回iter  第一个" << endl;
		iter = myset.lower_bound(100);
		cout << *iter << endl;
		cout << "6  定位 iter = upper_bound(key) >=key 返回iter 第一个" << endl;
		iter = myset.upper_bound(10);
		cout << *iter << endl;
		cout << "6.删除 int n=myset.erase(key) 返1 成功；返0 不成功" << endl;
		cout << "int n="<<myset.erase(8) << endl;
		for (auto iter1 = myset.begin(); iter1 != myset.end(); iter1++)
		{
			cout << *iter1 << endl;
		}
		cout << " 删除全部 myset.clear();" << endl;
		myset.clear();
		cout << "删除后大小 int nSize = myset.size();" << myset.size() << endl;
	
}