STL的学习

vector的学习

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void Print(int val){
	cout<<val<<endl;
}
//vector的学习使用 
void test01(){
	//创建一个vector容器 
	vector<int> v;
	//容器添加数据
	v.push_back(0);
	v.push_back(1);
	v.push_back(2);
	v.push_back(3);
	//迭代器遍历容器
	vector<int>::iterator itBegin = v.begin();//指向第一个迭代器 
	vector<int>::iterator itEnd = v.end();//指向最后一个迭代器的后面一个 


```C++
//while循环遍历
while(itBegin != itEnd){
	cout<<*itBegin<<endl;//指针访问 
	itBegin++;
} 

//for循环遍历
for(vector<int>::iterator it = v.begin(); it!=v.end();it++){
	cout<<*it<<endl;
} 

//for_each循环遍历
for_each(v.begin(),v.end(),Print);//初始位置，末尾位置，回调函数 
```

}
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//vector存放自定义类型数据
class Person{
public:
	Person(string name, int age){
		this->m_name = name;
		this->m_age = age;
	}
	string m_name;
	int m_age; 
}; 

void test02(){
	//新建一个容器 
	vector<Person>v;
	//新建person 
	Person p1("aaa",18);
	Person p2("bbb",28);
	// 容器中添加数据Person数据 
	v.push_back(p1);
	v.push_back(p2);
	//循环遍历
	for(vector<Person>::iterator it = v.begin();it!=v.end();it++){
		cout<<(*it).m_name<<"   "<<(*it).m_age<<endl;
	} 
}
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void test02(){
	vector< vector<int> >v;
	vector<int> v1;
	vector<int> v2;
	vector<int> v3;
	for(int i = 0; i<4; i++){
		v1.push_back(i);
		v2.push_back(i+1);
		v3.push_back(i+2);
	}
	v.push_back(v1);
	v.push_back(v2);
	v.push_back(v3);
	for(vector< vector<int> >::iterator it = v.begin(); it != v.end(); it++){
		for(vector<int>:: iterator st = (*it).begin(); st!=(*it).end();st++){
			cout<<*st<<" ";
		}
		cout<<endl;
	}
}
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vector<int> v;
for(int i = 0; i < 4; i++){
	v.push_back(i);
}
vector<int> v1(v.begin(),v.end());
vector<int> v2(10,5);
for(vector<int>::iterator it = v2.begin(); it != v2.end(); it++){
	cout<<*it<<endl;
}


vector的empty(),size(),capacity(),resize()的使用
vector<int> v;
for(int i = 0; i<17 ;i++){
	v.push_back(i);
} 
v.resize(18,1000);
if(v.empty()){
	cout<<"容器为空"<<endl; 
}else{
	cout<<"容器不为空"<<endl;
	cout<<"容器的大小: "<<v.size()<<endl;
	cout<<"容器的容量: "<<v.capacity()<<endl;
}
for(vector<int>::iterator it = v.begin(); it != v.end(); it++){
	cout<<*it<<endl;
}
cout<<"---------------------------------------"<<endl;
vector<int> vm;
vm.push_back(2100);
vm.push_back(2900);
vm.swap(v);
for(vector<int>::iterator it = v.begin(); it != v.end(); it++){
	cout<<*it<<endl;
}
vector<int> v;
//预留空间
v.reserve(100000);
int num = 0;
int* p = NULL;
for (int i = 0; i < 100000; i++) {
	v.push_back(i);
	if (p != &v[0]) {
		p = &v[0];
		num++;
	}
} 
cout << "num:" << num << endl;

string的学习

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string str5;
	str5.assign("hello c++",7);
	cout << "str5 = " << str5 << endl;
	string str6;
	str6.assign(str5);
	cout << "str6 = " << str6 << endl;
	string str7;
	str7.assign(5, 'x');
	cout << "str7 = " << str7 << endl;
	//添加字符串（两种方式） 
	string str = "abcdefg";
	str += "hi";
	str.append("jk");
	cout<<str<<endl;
	//从左往右查找 
	int pos1 = str.find("jk");
	cout<<pos1<<endl;
	//从右往左查找 
	int pos2 = str.rfind("jk");
	cout<<pos2<<endl;
	//替换函数 
	str.replace(0,2,"你好"); 
	cout<<str<<endl;
	//比较函数 
	/**
		字符串比较是按字符的ASCII码进行对比
		= 返回 0
		> 返回 1
		< 返回 -1
	**/
	string s1 = "abcdef";
	string s2 = "hbcdef";
	string s3 = "abcdef";
	int result1 = s1.compare(s2);
	int result2 = s1.compare(s3);
	cout<< result1 << "  "<<result2<<endl;
	//string单个字符存取
	cout<<s1[2]<<" : "<<s1.at(2)<<endl;
	//string的插入删除
	string st = "aceg";
	st.insert(1,"b");
	cout<<st<<endl; 
	st.insert(3,1,'d');
	cout<<st<<endl;
	st.erase(4,6);
	cout<<st<<endl;
	//string子串
	string test = st.substr(0,2); 
	cout<<test<<endl;

deque的学习

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	//定义一个双端数组 
	deque<int> d1;
	//添加元素 
	for(int i = 0; i < 10; i++){
		d1.push_back(i);
	}
	//把d1复制到d2 
	deque<int> d2(d1.begin(),d1.end());
	//迭代器遍历双端数组 
//	for(deque<int>::iterator it = d2.begin(); it!=d2.end();it++){
//		cout<<*it<<endl;
//	}
	//构造函数将n个elem拷贝给本身
	deque<int> d3(10,156);
//	for(deque<int>::iterator it = d3.begin(); it!=d3.end(); it++){
//		cout<<*it<<endl;
//	} 
	//拷贝构造函数
	deque<int> d4 = d3;
//	 for(deque<int>::iterator it = d4.begin(); it!=d4.end(); it++){
//		cout<<*it<<endl;
//	} 

	//deque的empty(),size(),resize() 
	cout<< d4.empty();
	if(d4.empty()){
		cout<<"deque为空"<<endl; 
	}
	else{
		cout<<"deque不为空"<<endl;
		cout<<"deque的元素个数： "<<d4.size()<<endl; 
	}
	//push_back(elem);
	d1.push_back(10078);
	//push_front(elem); 
	d1.push_front(78007);
	cout<<"删除前："<<endl ; 
	for(deque<int>::iterator it = d1.begin(); it!=d1.end();it++){
		cout<<*it<<endl;
	}
	cout<<"删除后："<<endl; 
	d1.pop_back(); //删除容器最后一个数据
	d1.pop_front();//删除容器第一个数据
	for(deque<int>::iterator it = d1.begin(); it!=d1.end();it++){
		cout<<*it<<endl;
	}
	cout<<"insert执行后"<<endl; 
	//insert的用法 
	d1.insert(d1.begin(),10000);
	d1.insert(d1.begin(),2,560);
	for(deque<int>::iterator it = d1.begin(); it!=d1.end();it++){
		cout<<*it<<"  ";
	}
	//erase的用法 
	cout<<endl;
	cout<<"erase执行后"<<endl; 
	d1.erase(d1.begin());
//	d1.erase(d1.begin(),d1.end());
//	d1.clear();
	for(deque<int>::iterator it = d1.begin(); it!=d1.end();it++){
		cout<<*it<<"  ";
	}
	
	//数据存取 
	cout<<endl;
	cout<<"at的使用: "<<d1.at(2)<<endl;
	cout<<"front的使用："<<d1.front()<<endl;
	cout<<"back的使用："<<d1.back()<<endl; 
	
	//排序
	cout<<endl;
	cout<<"排序后的结果： "<<endl; 
	sort(d1.begin(),d1.end());
	for(deque<int>::iterator it = d1.begin(); it!=d1.end();it++){
		cout<<*it<<"  ";
	}

list的学习

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	list<int> l1;
	list<int> l2;
	for(int i=0;i<5;i++){
		l1.push_back(i);
	}
	for(int i=5;i<10;i++){
		l2.push_back(i);
	}
//	l1.swap(l2);
	for(list<int>::iterator it = l1.begin(); it!=l1.end();it++){
		cout<<*it<<endl;
	}
	cout<<endl; 
	cout<<"删除后"<<endl;
	list<int>::iterator it = l1.begin();
	for(int i=0;i<2;i++)l1.insert(it,1000);
//	l1.erase(++it);
//	l1.remove(1000);
//	l1.reverse();
	l1.sort(compare);
	for(list<int>::iterator it = l1.begin(); it!=l1.end();it++){
		cout<<*it<<"  ";
	}

set的学习

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set<int> s;
	for(int i = 1; i < 5 ; i++)s.insert(i);
	for(set<int>::iterator it = s.begin(); it!=s.end(); it++){
		cout<<*it<<" ";
	}
	cout<<endl;
	s.insert(0);
	for(set<int>::iterator it = s.begin(); it!=s.end(); it++){
		cout<<*it<<" ";
	}
	cout<<endl;
	//find函数
	set<int>::iterator pos = s.find(3);
	if(pos!=s.end()){
		cout<<*pos<<endl;
	} else{
		cout<<"该数不存在"<<endl; 
	}
	int sum = s.count(1);
	cout<<"sum = "<<sum<<endl;

map的学习

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map<int,int> m;
m.insert(pair<int,int>(1,10)); 
m.insert(pair<int,int>(2,20)); 
m.insert(pair<int,int>(3,30)); 
m.insert(pair<int,int>(4,40)); 
cout<<"没有插入删除前"<<endl; 
for(map<int,int>::iterator mt = m.begin(); mt!=m.end(); mt++){
	cout<<"map的first: "<<mt->first<<"       map的second: "<<mt->second<<endl;
}
m.insert(make_pair(5,50));
m[6] = 60;
m.erase(m.begin());
cout<<"插入删除后"<<endl; 
for(map<int,int>::iterator mt = m.begin(); mt!=m.end(); mt++){
	cout<<"map的first: "<<mt->first<<"       map的second: "<<mt->second<<endl;
}
//count()
cout<<"key的个数： "<<m.count(0)<<endl;
//find() 
cout<<"查找key： "<<m.count(5)<<endl;