容器C++ ——STL常用容器

string容器

 string构造函数

#include<iostream>
using namespace std;
#include<string.h>
void test01() {string s1;//默认构造const char* str = "hello world";string s2(str);//传入char*cout << "s2=" << s2 << endl;string s3(s2);//传入stringcout << "s3=" << s3 << endl;string s4(5, 'a');//5个acout << "s4=" << s4 << endl;
}
int main() {test01();return 0;
}

 赋值操作

#include<iostream>
using namespace std;
#include<string.h>
//赋值操作
void test() {string str1;str1 = "hello";//=赋值cout << str1 << endl;string str2;str2 = str1;cout << str2 << endl;string str3;str3 = 'a';//可以把单个字符赋值给字符串cout << str3 << endl;string str4;str4.assign("hello c++");//assign赋值cout << str4 << endl;string str5;str5.assign("study", 3);//把字符串的前3个字符赋值给str5cout << str5 << endl;string str6;str6.assign(str5);cout << str6 << endl;string str7;str7.assign(6, 'w');cout << str7 << endl;
}
int main() {test();return 0;
}

字符串拼接

字符串末尾追加字符串

#include<iostream>
using namespace std;
#include<string.h>
//字符串拼接
void test() {string s1="hello";s1 += " world";//追加字符串cout << s1 << endl;s1 += '!';//追加字符cout << s1 << endl;string s2 = " study";s1 += s2;//追加字符串cout << s1 << endl;s1.append(" up up");cout << s1 << endl;s1.append(" eat food", 3);//把前n个字符拼接进来cout << s1 << endl;s1.append(s2);cout << s1 << endl;s1.append(s2, 0, 2);//从第0个位置截取2个字符，追加上cout << s1 << endl;
}
int main() {test();return 0;
}

string查找和替换

void test() {string s1 = "abcdefgcd";int pos = s1.find("cd");//3  返回d的位置。没有这个字串返回-1if (pos == -1) {cout << "未找到字符串" << endl;}else {cout << pos << endl;//pos=2   position 位置}//rfind//rfind从右往左查找，find从左往右查找pos = s1.rfind("cd");//7cout << pos << endl;
}//替换
void test02() {string s1 = "abcdefg";s1.replace(1, 3, "1111");//从1号位置起 3个字符，替换成1111cout << s1 << endl;//a1111efg
}

string的字符串比较

void test() {string s1 = "hello";string s2 = "hello";if (s1.compare(s2) == 0)cout<<"相等" << endl;else if(s1.compare(s2) > 0)cout << "s1>s2" << endl;else if(s1.compare(s2)<0)cout << "s1<s2" << endl;
}

string字符读取

void test() {string s1 = "hello";//cout << s1 << endl;for (int i = 0; i < s1.size(); i++)cout << s1[i] << " ";cout << endl;for (int i = 0; i < s1.size(); i++)cout << s1.at(i) << " ";s1[2] = 'a';//可以修改字符s1.at(1) = 'b';
}

string插入和删除

void test() {string str = "hello";str.insert(1, "111");//插入111cout << str << endl;str.erase(1, 3);//删除111.从1号位置删除3个字符
}

string字串

从字符串中获取想要的字串

void test02() {string email = "[e-mail]";//从邮箱中获取用户名int pos = email.find("@");cout << email.substr(0, pos) << endl;
}

vector  （可动态扩展的单端数组）

相似于数组，也称为单端数组。

和数组不同的是，vector可以动态扩展

#include<iostream>
using namespace std;
#include<vector>//vector头文件
//iterator迭代器
void printVector(vector<int>&v) {for (vector<int>::iterator it = v.begin(); it != v.end(); it++)cout << *it << " ";cout << endl;
}void test() {vector<int>v1;//默认构造 无参构造for (int i = 0; i < 10; i++)v1.push_back(i);printVector(v1);//通过区间方式进行构造vector<int>v2(v1.begin(), v1.end());printVector(v2);//n个 elem方式构造vector<int>v3(3, 5);//3个5printVector(v3);//拷贝构造vector<int>v4(v3);printVector(v4);
}
int main() {test();return 0;
}

vector赋值操作

void printVector(vector<int>& v) {for (vector<int>::iterator it = v.begin(); it != v.end(); it++)cout << *it << " ";cout << endl;
}void test() {vector<int>v1;for (int i = 0; i < 10; i++)v1.push_back(i);printVector(v1);//operator= 赋值vector <int>v2;v2 = v1;printVector(v2);//assignvector<int>v3;v3.assign(v1.begin(), v1.end());printVector(v3);//n个 elem方式赋值vector<int>v4;v4.assign(5, 100);//5个100printVector(v4);
}

vector容器  容量和大小

#include<iostream>
using namespace std;
#include<vector>//vector头文件void printVector(vector<int>& v) {for (vector<int>::iterator it = v.begin(); it != v.end(); it++)cout << *it << " ";cout << endl;
}
void test() {vector<int>v1;for (int i = 0; i < 10; i++) {v1.push_back(i);}printVector(v1);if (v1.empty())cout << "v1为空" << endl;else {cout << "v1不为空" << endl;cout << v1.capacity() << endl;cout << v1.size() << endl;}//重新指定大小 v1.resize(15,100);//指定用100填充   v1.resize(15);   printVector(v1);//如果重新指定的比原来长，默认用0填充v1.resize(5);//指定的比原来短,超出的部分会删掉printVector(v1);
}int main() {test();return 0;
}

 插入和删除

void test() {vector<int>v1;//尾插v1.push_back(10);v1.push_back(20);v1.push_back(30);v1.push_back(40);v1.push_back(50);//遍历printVector(v1);//尾删v1.pop_back();printVector(v1);//插入 第一个参数是迭代器v1.insert(v1.begin(), 100);//起始迭代器printVector(v1);v1.insert(v1.begin(), 2, 1000);//在起始迭代器处插入2个1000printVector(v1);//删除v1.erase(v1.begin());//在起始迭代器处删除printVector(v1);//清空//v.clear();v1.erase(v1.begin(), v1.end());//提供一个区间printVector(v1);
}

vector数据存取

void test() {vector<int>v1;for (int i = 0; i < 10; i++) {v1.push_back(i);//尾插法}for (int i = 0; i < v1.size(); i++) {cout << v1[i] << " ";}cout << endl;for (int i = 0; i < v1.size(); i++)cout << v1.at(i) << " ";cout << endl;//获取第一个元素cout << v1.front() << endl;//获取最后一个元素cout << v1.back() << endl;
}

vector互换容器

void test() {vector<int>v;int num = 0;//统计开辟次数int* p = NULL;for (int i = 0; i < 10000; i++) {v.push_back(i);if (p != &v[0]) {p = &v[0];num++;}}cout << num << endl;
}

deque容器 （双端数组）

#include<iostream>
using namespace std;
#include<deque>
void printDeque(const deque<int>&d) {for (deque<int>::const_iterator it = d.begin(); it != d.end(); it++)cout << *it << " ";cout << endl;
}
void test() {deque<int>d1;for (int i = 0; i < 10; i++){d1.push_back(i);//插数}printDeque(d1);deque<int>d2(d1.begin(), d1.end());printDeque(d2);deque<int>d3(5, 100);printDeque(d3);deque<int>d4(d3);printDeque(d4);
}
int main() {test();return 0;
}

赋值

void printDeque(const deque<int>&d) {//const使其只读for (deque<int>::const_iterator it = d.begin(); it != d.end(); it++)cout << *it << " ";cout << endl;
}
void test() {deque<int>d1;for (int i = 0; i < 10; i++) {d1.push_back(i);}printDeque(d1);//operator= 赋值deque<int>d2;d2 = d1;printDeque(d2);//assign 赋值deque<int>d3;d3.assign(d1.begin(), d1.end());printDeque(d3);deque<int>d4;d4.assign(5, 6);printDeque(d4);
}

deque容器大小

void test() {deque<int>d1;for (int i = 0; i < 10; i++)d1.push_back(i);if (d1.empty())cout << "d1为空" << endl;else {cout << "d1不为空" << endl;cout << d1.size() << endl;//deque没有容量的概念，可以无限放//重新指定大小//d1.resize(15);d1.resize(15, 3);//多的用3填充printDeque(d1);}
}

deque容器的插入和删除

#include<iostream>
using namespace std;
#include<deque>
void printDeque(const deque<int>d) {//const防止误修改for (deque<int>::const_iterator it = d.begin(); it != d.end(); it++)cout << *it << " ";cout << endl;
}
void test() {deque<int>d1;//尾插d1.push_back(10);d1.push_back(20);//头插d1.push_front(30);d1.push_front(40);printDeque(d1);//40 30 10 20//尾删d1.pop_back();printDeque(d1);//40 30 10//头删d1.pop_front();printDeque(d1);//30 10
}void test02() {deque<int>d1;//尾插d1.push_back(10);d1.push_back(20);//头插d1.push_front(30);d1.push_front(40);printDeque(d1);//40 30 10 20//insert插入d1.insert(d1.begin(), 1000);printDeque(d1);//1000 40 30 10 20d1.insert(d1.begin(), 3, 9);printDeque(d1);//9 9 9 1000 40 30 10 20//删除指定位置deque<int>::iterator it = d1.begin();it+=5;d1.erase(it);printDeque(d1);//9 9 9 1000 40 10 20//按照区间的形式删除d1.erase(d1.begin(), it);//10 20printDeque(d1);//按照区间进行插入deque<int>d2;d2.push_back(1);d2.push_back(2);d2.push_back(3);d1.insert(d1.begin(), d2.begin(), d2.end());printDeque(d1);//1 2 3 10 20//清空d1.clear();printDeque(d1);//只剩一个换行了
}
int main() {test();test02();return 0;
}

数据存取

void test() {deque<int>d1;d1.push_back(10);d1.push_back(20);d1.push_back(30);d1.push_front(100);d1.push_front(200);d1.push_front(300);//[]方式for (int i = 0; i < d1.size(); i++)cout << d1[i] << endl;//at方式for (int i = 0; i < d1.size(); i++)cout << d1.at(i) << endl;cout << "第一个元素：" << d1.front() << endl;cout << "最后一个元素：" << d1.back() << endl;
}

排序操作

对于支持随机访问的迭代器的容器，都可以利用sort算法直接对其进行排序
vector容器也可以利用sort进行排序

#include<deque>//双端数组
#include<algorithm>//标准算法sort(d.begin(), d.end());//默认升序

stack （栈）

//栈不允许有遍历
//栈可以判断是否为空 empty
//栈可以计算大小 size

#include<iostream>
using namespace std;
#include<stack>
//栈 stack容器
void test() {//先进后出stack<int>s;//默认构造s.push(10);//入栈s.push(20);s.push(30);while (!s.empty()) {cout << s.top() << " ";//输出栈顶元素s.pop();//出栈}cout << endl;cout << s.size() << endl;
}
int main() {test();return 0;
}

queue （队列）

先进先出

只有队头和队尾被看到，不允许遍历

#include<iostream>
using namespace std;
#include<queue>
class Person {
public:Person(string name, int age) {this->m_Name = name;this->m_Age = age;}string m_Name;int m_Age;
};
void test() {//先进先出//创建队列queue<Person>q;//准备数据Person p1("唐僧", 30);Person p2("孙悟空", 200);Person p3("猪八戒", 100);//入队q.push(p1);q.push(p2);q.push(p3);while (!q.empty()) {cout << q.front().m_Name << q.front().m_Age<< " ";//查看队头元素cout << q.back().m_Name << q.back().m_Age << " ";//查看队尾元素q.pop();//出队}cout << endl;cout << q.size() << endl;
}
int main() {test();return 0;
}

list链表

list容器构造

#include<iostream>
using namespace std;
#include<list>
//链表由节点构成
//节点包括 数据域，指针域//list容器构造函数
void printList(const list<int>&L) {for (list<int>::const_iterator it = L.begin(); it != L.end(); it++) {cout << *it << " ";}cout << endl;
}
void test() {//创建 list容器list<int>L1;//添加数据L1.push_back(10);L1.push_back(20);L1.push_back(30);L1.push_back(40);//遍历容器printList(L1);//区间方式构造list<int>L2(L1.begin(), L1.end());printList(L2);//拷贝构造list<int>L3(L2);printList(L3);//n个 elemlist<int>L4(5, 100);printList(L4);
}
int main() {test();return 0;
}

list赋值和交换

#include<iostream>
using namespace std;
#include<list>
void printList(const list<int>&L) {for (list<int>::const_iterator it = L.begin(); it != L.end(); it++) {cout << *it << " ";}cout << endl;
}
//赋值
void test() {list<int>L1;L1.push_back(10);L1.push_back(20);L1.push_back(30);L1.push_back(40);printList(L1);list<int> L2;L2 = L1;printList(L2);list<int>L3;L3.assign(L2.begin(), L2.end());printList(L3);list<int>L4;L4.assign(5, 3);printList(L4);
}//交换
void test02() {list<int>L1;L1.push_back(10);L1.push_back(20);L1.push_back(30);L1.push_back(40);printList(L1);list<int>L2;L2.assign(5, 100);printList(L2);//交换L1.swap(L2);printList(L1);printList(L2);
}
int main() {test();test02();return 0;
}

list大小

if (L1.empty()) {cout << "L1为空" << endl;
}
else {cout << "L1不为空" << endl;cout << "L1的元素个数" << L1.size() << endl;
}//重新指定大小
L1.resize(10,10000);
printList(L1);L1.resize(3);
printList(L1);

list插入和删除

void test() {list<int>L1;L1.push_back(10);//尾插L1.push_back(20);L1.push_back(30);L1.push_front(100);//头插L1.push_front(200);L1.push_front(300);printList(L1);//300 200 100 10 20 30//尾删L1.pop_back();printList(L1);//300 200 100 10 20//头删L1.pop_front();printList(L1);//200 100 10 20//insert插入list<int>::iterator it = L1.begin();//创建一个迭代器L1.insert(++it, 1000);printList(L1);//200 1000 100 10 20//删除it = L1.begin();L1.erase(++it);printList(L1);//200 100 10 20L1.push_back(10);//移除,可以删除所有与 elem值匹配的元素L1.remove(10);printList(L1);//200 100 20//清空L1.clear();printList(L1);
}

list的数据存取

不支持随机访问

//list容器中的数据存取
void test() {list<int>L1;L1.push_back(1);L1.push_back(2);L1.push_back(3);L1.push_back(4);cout << L1.front() << " " << L1.back() << endl;//1 4
}

//验证迭代器是不支持随机访问的
list<int>::iterator it = L1.begin();
it++;//支持双向
it--;
//it+=2; 错误 不能随机访问

list反转和排序

bool myCompare(int v1,int v2) {//实现排序降序return v1 > v2;//让L1>L2
}
void test() {list<int>L1;L1.push_back(1);L1.push_back(3);L1.push_back(2);L1.push_back(4);printList(L1);L1.reverse();//反转printList(L1);L1.sort();//排序  默认升序printList(L1);L1.sort(myCompare);//降序printList(L1);
}

list排序案例

以年龄做升序，年龄相同做降序

#include<iostream>
using namespace std;
#include<list>
#include<string>
//自定义数据类型
class Person {
public:Person(string name,int age,int height) {this->m_Name = name;this->m_Age = age;this->m_Height = height;}string m_Name;int m_Age;int m_Height;
};//指定排序规则
bool comparePerson(Person &p1,Person &p2) {//按照年龄升序if (p1.m_Age == p2.m_Age){//年龄相同，按照升高降序return p1.m_Height > p2.m_Height;}return p1.m_Age < p2.m_Age;
}
void test() {list<Person>L1;//创建容器//准备数据Person p1("刘备", 35, 175);Person p2("曹操", 45, 180);Person p3("孙权", 40, 170);Person p4("赵云", 25, 190);Person p5("张飞", 35, 160);Person p6("关羽", 35, 200);//插入数据L1.push_back(p1);L1.push_back(p2);L1.push_back(p3);L1.push_back(p4);L1.push_back(p5);L1.push_back(p6);for (list<Person>::iterator it = L1.begin(); it != L1.end(); it++) {cout << "姓名：" << (*it).m_Name << " 年龄：" << (*it).m_Age << " 身高：" << (*it).m_Height << endl;}cout << "----------------------------------------" << endl;//排序L1.sort(comparePerson);for (list<Person>::iterator it = L1.begin(); it != L1.end(); it++) {cout << "姓名：" << (*it).m_Name << " 年龄：" << (*it).m_Age << " 身高：" << (*it).m_Height << endl;}
}
int main() {test();return 0;
}

set/multiset

元素在插入时自动排序

属于关联式容器，底层是二叉树结构

set不允许有重复的元素

multiset允许有重复的元素

set容器构造和赋值

#include<iostream>
using namespace std;
#include<set>
void printSet(set<int>&s) {for (set<int>::iterator it = s.begin(); it != s.end(); it++) {cout << *it << " ";}cout << endl;
}
void test() {//set容器构造和赋值set<int>s1;s1.insert(10);//插入s1.insert(40);s1.insert(20);s1.insert(30);s1.insert(30);printSet(s1);//10 20 30 40 自动升序排列 不允许插入重复值//拷贝构造set<int>s2(s1);printSet(s2);//10 20 30 40//赋值set<int>s3;s3 = s2;printSet(s3);//10 20 30 40//大小if (s1.empty()) {cout << "s1为空" << endl;}else {cout << "s1不为空" << endl;cout << "s1的大小" << s1.size() << endl;}set<int>s4;s1.insert(4);s1.insert(1);//交换s1.swap(s4);printSet(s1);//1 4printSet(s4);//10 20 30 40//删除s2.erase(s2.begin());printSet(s2);//20 30 40//删除的重载版本————删除指定值s2.erase(30);printSet(s2);//20 40//清空s2.clear();printSet(s2);//查找set<int>::iterator pos = s3.find(30);//返回元素的迭代器，若未找到返回endif (pos != s3.end()) {cout << "找到元素" << *pos << endl;}else {cout << "未找到" << endl;}//统计30的个数int num = s3.count(30);//set统计结果 只有为0或1cout << "num=" << num << endl;}
int main() {test();return 0;
}

 大小和交换

pair对组创建

成对出现的数据，利用对组可以返回两个数据

void test() {//第一种方式pair<string, int>p("tom", 20);cout << "姓名:" << p.first << " 年龄:" << p.second << endl;//第二种方式pair<string, int>p2 = make_pair("jerry", 30);cout << "姓名:" << p2.first << " 年龄:" << p2.second << endl;
}

内置类型指定排序规则

#include<iostream>
using namespace std;
#include<set>
//set容器排序//利用仿函数指定set容器排序规则
class myCompare {
public:bool operator()(int v1,int v2)const {return v1 > v2;//做降序}
};
void test() {set<int,myCompare>s1;s1.insert(4);s1.insert(2);s1.insert(6);s1.insert(3);s1.insert(5);for (set<int>::iterator it = s1.begin(); it != s1.end(); it++)cout << *it << " ";cout << endl;
}
int main() {test();return 0;
}

set存放自定义数据类型 指定规则

#include<iostream>
using namespace std;
#include<set>
#include<string>
//自定义数据类型
class Person {
public:Person(string name, int age) {this->m_Name = name;this->m_Age = age;}string m_Name;int m_Age;
};
//指定排序规则
//仿函数
class comparePerson {
public:bool operator()(const Person& p1, const Person& p2)const {//使用了Person，要把Person写到其前面//按照年龄 降序return p1.m_Age > p2.m_Age;}
};
void test() {set<Person,comparePerson>s;Person p1("刘备", 35);Person p2("曹操", 45);Person p3("孙权", 40);Person p4("赵云", 25);Person p5("张飞", 35);s.insert(p1);s.insert(p2);s.insert(p3);s.insert(p4);s.insert(p5);for (set<Person,comparePerson>::iterator it = s.begin(); it != s.end(); it++) {cout << "姓名：" << it->m_Name << " 年龄：" << it->m_Age <<endl;}
}
int main() {test();return 0;
}

map/multimap

插入和删除

#include<iostream>
using namespace std;
#include<map>
//map容器 构造和赋值
void printMap(map<int, int>& m) {for (map<int, int>::iterator it = m.begin(); it != m.end(); it++) {cout << "key=" << (*it).first << " value="<<it->second << endl;}cout << endl;
}
void test() {map<int, int>m;m.insert(pair<int, int>(1, 10));m.insert(pair<int, int>(3, 30));m.insert(pair<int, int>(2, 20));m.insert(pair<int, int>(4, 40));printMap(m);//拷贝构造map<int, int>m2(m);printMap(m2);//赋值map<int, int>m3;m3 = m2;printMap(m3);//大小if (m.empty()) {cout << "map容器为空" << endl;}else {cout << "map的大小为:" << m.size() << endl;}map<int, int>m4;m4.insert(pair<int, int>(8, 100));m4.insert(pair<int, int>(6, 300));m4.insert(pair<int, int>(7, 400));m4.insert(pair<int, int>(9, 500));printMap(m4);//交换m.swap(m4);cout << "交换后" << endl;printMap(m);printMap(m4);//插入map<int, int>m5;//第一种m5.insert(pair<int, int>(10, 100));//第二种m5.insert(make_pair(20, 200));//第三种m5.insert(map<int, int>::value_type(30, 300));//第四种m5[40] = 400;//不建议使用cout << "输出m5" << endl;printMap(m5);//删除m5.erase(m5.begin());printMap(m5);m5.erase(20);//按照 key删除printMap(m5);//清空m5.erase(m5.begin(), m5.end());printMap(m5);//清空m4.clear();
}
int main() {test();return 0;
}

查找和统计

#include<iostream>
using namespace std;
#include<map>
void test() {//查找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));map<int,int>::iterator pos = m.find(3);//按 key查找     find返回的是迭代器if (pos != m.end())cout << "查找到了元素 key=" << (*pos).first << " value=" << pos->second << endl;elsecout << "未找到元素" << endl;//统计//map不允许插入重复key 元素，count统计而言 结果要么是0，要么是1//multimap的count统计可能大于1int num = m.count(3);cout << "num=" << num << endl;
}
int main() {test();return 0;
}

排序

#include<iostream>
using namespace std;
#include<map>
class myCompare {
public:bool operator()(int v1,int v2)const{//第一个括号是要重载的运算符，第二个小括号是参数列表//降序return v1 > v2;}
};
void test() {map<int, int,myCompare>m;//两种插入方法m.insert(pair<int, int>(1, 10));//存储两个值m.insert(make_pair(2, 20));//无需显式指定类型（自动推导）m.insert(make_pair(6, 60));m.insert(make_pair(4, 40));m.insert(make_pair(5, 50));for (map<int, int,myCompare>::iterator it = m.begin(); it != m.end(); it++)cout << "key=" << it->first << " value=" << it->second << endl;
}
int main() {test();return 0;
}