C++ STL 练手(deque的使用)
2018-02-12 本文已影响20人
863cda997e42
#include <deque>
#include <iostream>
#include <algorithm>
#include <stdexcept>
using namespace std;
void print(int num)
{
cout << num << " ";
}
int main()
{
//1. 初始化
deque<int> v;
deque<int>::iterator iv;
v.assign(10, 2);//将10个值为2的元素赋到deque中
cout << v.size() << endl; //返回deque实际含有的元素数量
cout << endl;
//2. 添加
v.push_front(666);
for (int i = 0; i < 10; i++)
v.push_back(i);
for_each(v.begin(), v.end(), print);//需要#include <algorithm>
cout << endl;
cout << v.size() << endl;
cout << endl;
//3. 插入及遍历、逆遍历
v.insert(v.begin() + 3, 99);
v.insert(v.end() - 3, 99);
for_each(v.begin(), v.end(), print);
cout << endl;
for_each(v.rbegin(), v.rend(), print);//在逆序迭代器上做++运算将指向容器中的前一个元素
cout << endl;
//一般遍历写法
for(iv = v.begin(); iv != v.end(); ++iv)
cout << *iv << " ";
cout << endl;
cout << endl;
//4. 删除
v.erase(v.begin() + 3);
for_each(v.begin(), v.end(), print);
cout << endl;
v.insert(v.begin() + 3, 99);//还原
v.erase(v.begin(), v.begin() + 3); //注意删除了3个元素而不是4个
for_each(v.begin(), v.end(), print);
cout << endl;
v.pop_front();
v.pop_back();
for_each(v.begin(), v.end(), print);
cout << endl;
cout << endl;
//5. 查询
cout << v.front() << endl;
cout << v.back() << endl;
//危险的做法,但一般我们就像访问数组那样操作就行
//for (int i = 15; i < 25; i++)
//cout << "Element " << i << " is " << v[i] << endl;
//安全的做法
int i;
try
{
for (i = 15; i < 25; i++)
cout << "Element " << i << " is " << v.at(i) << endl;
}
catch (out_of_range err)//#include <stdexcept>
{
cout << "out_of_range at " << i << endl;
}
cout << endl;
//6. 清空
v.clear();
cout << v.size() << endl;//0
for_each(v.begin(), v.end(), print); //已经clear,v.begin()==v.end(),不会有任何结果。
return 0;
}
```