一 multimap
key可以重复
案例：
公司：
销售部：2名
技术研发部：1名
财务部：4名
人员信息：姓名，年龄，电话，工资等组成
通过multimap进行信息的插入，保存，显示
分部门显示员工信息
#include <iostream>
#include <string>
#include <algorithm>
#include <map>
using namespace std;
class Employee
{
private:
int id;
string name;
public:
Employee(int i, string n)
{
id = i;
name = n;
}
void show()
{
cout << "工号：" << id << "姓名："<<name<<endl;
}
};
int main(void)
{
Employee e1(1000,"aa");
Employee e2(1001, "bb");
Employee e3(1002, "cc");
Employee e4(1003, "dd");
Employee e5(1004, "ee");
Employee e6(1005, "ff");
Employee e7(1006, "gg");
Employee e8(1007, "ll");
multimap<string, Employee> m;
//销售部有2名员工
m.emplace(make_pair("sale", e1));
m.emplace(make_pair("sale", e2));
//研发部有两名员工
m.emplace(make_pair("development", e3));
m.emplace(make_pair("development", e8));
//财务部有四名员工
m.emplace(make_pair("finance",e4));
m.emplace(make_pair("finance", e5));
m.emplace(make_pair("finance", e6));
m.emplace(make_pair("finance", e7));
cout << m.count("Finance") << endl;
for (auto it = m.begin(); it != m.end(); it++)
{
cout << "部门：" << it->first << endl;
it->second.show();
}
return 0;
}
二 deque
双端数组，接口和vector类似，在头部和尾部非常迅速，但是在中部添加元素比较费时，需要添加头文件#include<deque>
#include <iostream>
#include <string>
#include <deque>
using namespace std;
int main(void)
{
int data[5] = { 1,2,3,4,5 };
deque<int> d1;
deque<int> d2(data, data + 5);
deque<int> d3(10,1);
for (auto &d : d2)
{
cout << d << " ";
}
cout << endl;
d2.emplace_back(6);
d2.emplace_front(0);
for (auto &d : d2)
{
cout << d << " ";
}
cout << endl;
d2.pop_back();
d2.pop_front();
d2.front() = 10000;
d2.back() = 20000;
for (auto &d : d2)
{
cout << d << " ";
}
cout << endl;
return 0;
}
三 容器适配器
stack（LIFO）
queue(fifo)
priority_queue()
3.1 stack
#include <stack>
#include <iostream>
#include <time.h>
using namespace std;
int main(void)
{
stack<int> s;
srand(time(NULL));
int num;
for (int i = 0; i < 10; i++)
{
num = rand() % 10;
s.push(num);
cout << num << "进栈成功" << endl;
}
cout << "栈顶元素是：" << s.top() << endl;
cout << "栈的大小：" << s.size() << endl;
//栈和队列不存在遍历，不存在迭代器
while (!s.empty())
{
cout << s.top() << "出栈" << endl;
s.pop();
}
s.pop();
return 0;
}
3.2 队列
#include <queue>
#include <iostream>
#include <time.h>
using namespace std;
int main(void)
{
queue<int> q;
for (int i = 0; i < 10; i++)
{
q.push(i);
cout << i << " 进队成功" << endl;
}
cout << "队头元素：" << q.front() << endl;
cout << "队尾元素：" << q.back() << endl;
cout << "队列大小：" <<q.size()<< endl;
while (!q.empty())
{
cout << q.front() << "出队" << endl;
q.pop();
}
return 0;
}
3.3 优先队列
#include <queue>
#include <iostream>
#include <time.h>
using namespace std;
int main(void)
{
//priority_queue<int> p;
//priority_queue<int, vector<int>, less<int>> p; //等价于priority_queue<int> p;
priority_queue<int, deque<int>, greater<int>> p;
srand(time(NULL));
int num;
for (int i = 0; i < 10; i++)
{
num = rand() % 10;
p.emplace(num);
cout << num << "进队成功" << endl;
}
cout << "队头元素 " << p.top() << endl;
cout << "队列长度：" << p.size() << endl;
while (!p.empty())
{
cout << p.top() <<"出队"<<endl;
p.pop();
}
return 0;
}
四 异常
4.1 什么是异常
异常处理就是处理程序中错误，所谓错误就是程序运行时发生的一些异常事件（栈溢出，数组下标越界等）
4.2 异常的语法
分为三个部分：
抛出异常：throw
检测异常：
try
{
可能发生异常的语句
}
捕获异常:
catch(异常类型 变量名)
{
异常处理语句
}
抛出异常：throw关键字，当执行throw之后，try语句块就会立即结束，运行catch中的异常处理的语句。
throw 表达式、常量、变量
throw的用法和惹他于任内类似，throw是抛出一个值，return是上一级调用的函数
#include <iostream>
using namespace std;
int Div(int x, int y)
{
if (0 == y)
{
//return -1;
//throw 0; //抛出异常
throw 'a';
}
return x / y;
}
int main(void)
{
int a, b;
cin >> a >> b;
try //把可能出现异常的代码放在try语句中
{
cout << Div(a, b) << endl;
cout << "hello world" << endl;
}
catch(int)
{
cout << "zero exception" << endl;
}
catch (char)
{
cout << "char exception" << endl;
}
cout << "nihao nanjing" << endl;
return 0;
}
4.3 异常的声明
#include <iostream>
using namespace std;
//int Div(int x, int y); //可能抛出任何异常
//int Div(int x, int y) throw(int, char); //只能抛出int,char类型的异常
int Div(int x, int y) throw(); //不允许抛出任何异常
int main(void)
{
int a, b;
cin >> a >> b;
try //把可能出现异常的代码放在try语句中
{
cout << Div(a, b) << endl;
cout << "hello world" << endl;
}
catch(int)
{
cout << "zero exception" << endl;
}
catch (char)
{
cout << "char exception" << endl;
}
catch (double)
{
cout << "double exception" << endl;
}
cout << "nihao nanjing" << endl;
return 0;
}
int Div(int x, int y) throw()
{
if (0 == y)
{
//return -1;
//throw 0; //抛出异常
//throw 'a';
throw 3.14;
}
return x / y;
}
4.4 异常对象
#include <iostream>
using namespace std;
int Div(int x, int y); //可能抛出任何异常
//int Div(int x, int y) throw(int, char); //只能抛出int,char类型的异常
//int Div(int x, int y) throw(); //不允许抛出任何异常
class Test
{
public:
Test()
{
cout << "Test的构造函数" << endl;
}
Test(const Test &obj)
{
cout << "Test的拷贝构造" << endl;
}
void print()
{
cout << "Test exception" << endl;
}
~Test()
{
cout << "Test的析构函数" << endl;
}
};
int main(void)
{
int a, b;
cin >> a >> b;
try //把可能出现异常的代码放在try语句中
{
cout << Div(a, b) << endl;
cout << "hello world" << endl;
}
catch(int)
{
cout << "zero exception" << endl;
}
catch (char)
{
cout << "char exception" << endl;
}
catch (double)
{
cout << "double exception" << endl;
}
/*catch (Test t) //调用拷贝构造函数
{
t.print();
}*/
/*catch (Test &t) //推荐
{
t.print();
}*/
catch (Test *t)
{
t->print();
delete t; //需要手动释放
}
cout << "nihao nanjing" << endl;
return 0;
}
int Div(int x, int y)
{
if (0 == y)
{
//return -1;
//throw 0; //抛出异常
//throw 'a';
//throw 3.14;
//throw Test();
throw new Test();
}
return x / y;
}
4.5 标准异常库
#include <iostream>
#include <exception>
using namespace std;
int Div(int x, int y); //可能抛出任何异常
//int Div(int x, int y) throw(int, char); //只能抛出int,char类型的异常
//int Div(int x, int y) throw(); //不允许抛出任何异常
class Exception :public exception
{
private:
string Errmsg;
public:
Exception(string e) :Errmsg(e)
{
}
virtual const char* what() const throw() //虚函数重写
{
return Errmsg.data();
}
};
int main(void)
{
int a, b;
cin >> a >> b;
try
{
cout << Div(a,b) << endl;
}
catch (const std::exception &e)
{
cout << e.what() << endl;
}
return 0;
}
int Div(int x, int y)
{
if (0 == y)
{
//return -1;
//throw 0; //抛出异常
//throw 'a';
//throw 3.14;
//throw Test();
throw Exception("除数不能为0");
throw bad_alloc();
}
return x / y;
}
4.6 自定义stack
优点:
1.pop()-->返回下一个元素
2.如果stack为空，pop和top会抛出异常
#include <iostream>
#include <exception>
#include <deque>
using namespace std;
template <typename T>
class Stack
{
protected:
std::deque<T> c;
public:
class ReadEmptyStack :public exception
{
public:
virtual const char* what() const throw()
{
return "read empty stack";
}
};
//typename std::deque<T>::size_type size() const //类型依赖于模板参数的限定名，前面必须加typename
auto size() const
{
return c.size();
}
bool empty() const
{
return c.empty();
}
void push(const T& elem)
{
c.push_back(elem);
}
T pop()
{
if (c.empty())
{
throw ReadEmptyStack();
}
T elem(c.back());
c.pop_back();
return elem;
}
T& top()
{
if (c.empty())
{
throw ReadEmptyStack();
}
return c.back();
}
};
int main(void)
{
try
{
Stack<int> st;
st.push(1);
st.push(2);
st.push(3);
st.push(4);
cout << st.pop() << endl;
cout << st.pop() << endl;
st.top() = 77; //修改栈顶元素为77
st.push(5);
st.push(6);
st.pop();
cout << "st.size():" << st.size() << endl;
while (!st.empty())
{
st.pop();
}
st.pop();
}
catch (const std::exception& e)
{
cout << e.what() << endl;
}
return 0;
}
五 string
和vector接口类似，是一种特殊的容器，除了具有vector的内存特性之外，专门用于对字符串的处理操作。
#include <iostream>
#include <string>
#include <cstring>
using namespace std;
int main(void)
{
string s1;
string s2("helloworld");
string s3(10, 'a');
string s4(s2);
cout << s2 << endl;
/*cin >> s1;
cout << s1 << endl;*/
s1 += "helloworld";
if (s1 == s2)
{
}
//s1 = s1 + s2;
s1 += s2;
cout << s1 << endl;
//string的存取
string s("helloworld");
cout << s[1] << endl;
s[1] = 'x';
for (auto it = s.begin(); it != s.end(); it++)
{
cout << *it << " ";
}
cout << endl;
for (auto &s : s)
{
cout << s << " ";
}
cout << endl;
//string的c_str
/*char buf[32] = { 0 };
strcpy_s(buf, s.c_str());
cout << buf << endl;*/
//string 的copy
char buf[32] = { 0 };
s.copy(buf, 5); //拷贝前5个字节到buf中
cout << buf << endl;
//string的长度
cout << s.length() << endl;
cout << s.size() << endl;
s.reserve(100);
cout << s.capacity() << endl;
s.shrink_to_fit();
cout << s.capacity() << endl;
if (s.empty())
{
cout << "字符串是空" << endl;
}
//string的赋值
s = "helloworld";
const char *ss = "this is test";
s1.assign(ss);
cout << s1 << endl;
s1.assign(ss, 7);
cout << s1 << endl;
s1.assign(5, 'a'); //把5个a赋值给s1
cout << s1 << endl;
s1.assign(s2); //把s2 赋值给s1
cout << s1 << endl;
s1.assign(s4, 4, 3); //把s4从第四个开始的三个字符赋值给当前字符串
cout << s1 << endl;
//string的拼接
s1 += "1234";
cout << s1 << endl;
s1 += s2;
cout << s1 << endl;
s1.append(ss);
s1.append(s2);
s1.append(ss, 2); //拼接ss的前两个字节
s1.append(s2, 4, 2);
cout << s1 << endl;
s1.append(10, 'x');
cout << s1 << endl;
//string的比较
if (s1 == s2)
{
}
if (s1.compare(s2) > 0)
{
}
if (s1.compare(ss) < 0)
{
cout << "s1 < ss" << endl;
}
//string字串
cout << s1.substr() << endl;
cout << s1.substr(5, 6)<<endl; //从第五个开始，往后输出6个字符
//string的查找和替换
int p = s1.find('o');
cout << p << endl;
p = s1.find('o', 8); //从第八个字符向后找 ,不存在返回-1
cout << p << endl;
p = s1.find("ll");
cout << p << endl;
p = s1.find(s2);
cout << p << endl;
p = s1.find(ss);
cout << p << endl;
p = s1.rfind('o');
cout << p << endl;
s1.replace(5, 3, "xxx");
cout << s1 << endl;
string s9("helloworldhelloworldhelloworldhelloworldhelloworldhelloworld");
//使用上述任意方法，将s3中所有"world"替换成"x"
p = s9.find("world");
while (p != -1)
{
s9.replace(p, strlen("world"), "x");
p = s9.find("world", p + strlen("x"));
}
cout << s9 << endl;
//string的插入和删除
s1.insert(0, "this is");
cout << s1 << endl;
s1.insert(10, s2);
cout << s1 << endl;
s1.insert(0, 5, 'x');
cout << s1 << endl;
s1.erase(s1.begin());
cout << s1 << endl;
s1.erase(0, 20);
cout << s1 << endl;
s1.erase(++s1.begin(),s1.end());
cout << s1 << endl;
return 0;
}