string容器
string构造函数
cpp
#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string
cout << "s3=" << s3 << endl;
string s4(5, 'a');//5个a
cout << "s4=" << s4 << endl;
}
int main() {
test01();
return 0;
}赋值操作
cpp
#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str5
cout << 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
cpp
#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
cpp
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-1
if (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");//7
cout << 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1111
cout << s1 << endl;//a1111efg
}string的字符串比较
cpp
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
cpp
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
cpp
void test() {
string str = "hello";
str.insert(1, "111");//插入111
cout << 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
cpp
void test02() {
string email = "[email protected]";
//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
cpp
#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5
printVector(v3);
//拷贝构造
vector<int>v4(v3);
printVector(v4);
}
int main() {
test();
return 0;
}vector赋值操作
cpp
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);
//assign
vector<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100
printVector(v4);
}vector容器 容量和大小
cpp
#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
cpp
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1000
printVector(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
cpp
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
cpp
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）
cpp
#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
cpp
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
cpp
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
cpp
#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 20
d1.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 20
printDeque(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
cpp
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
cpp
#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
cpp
#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
cpp
#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
cpp
#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 elem
list<int>L4(5, 100);
printList(L4);
}
int main() {
test();
return 0;
}list赋值和交换
cpp
#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
cpp
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
cpp
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 20
L1.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
cpp
//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
}
cpp
//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
cpp
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
cpp
#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
cpp
#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 4
printSet(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end
if (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1
cout << "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
cpp
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
cpp
#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
cpp
#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
cpp
#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
cpp
#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;
else
cout << "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1
int num = m.count(3);
cout << "num=" << num << endl;
}
int main() {
test();
return 0;
}排序
cpp
#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;
}