C++ STL Vector

#include <vector>  
#include <iostream>  
#include <algorithm>  
#include <stdexcept>  
using namespace std;  
   
void print(int num)  
{  
    cout << num << " ";  
}  
   
int main()  
{  
    //1. 初始化  
    vector<int> v;  
    vector<int>::iterator iv;  
 
    v.reserve(100); //设置vector最小的元素容纳数量  
    v.assign(10, 2); //将10个值为2的元素赋到vector中  
    cout << v.capacity() << endl; //返回vector所能容纳的元素数量(在不重新分配内存的情况下）  
    cout << v.size() << endl; //返回Vector实际含有的元素数量  
    cout << "-------------1--------------" << endl; 
 
    //2. 添加  
    //注意：push_front()只适用于list和deque容器类型  
    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 << "-------------2--------------" << endl;  
 
    //3. 插入及遍历、逆遍历  
    v.insert(v.begin() + 3, 99);  
    v.insert(v.end() - 3, 88);  
    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;  
    cout << "-------------3--------------" << endl;  
 
    //一般遍历写法  
    for(iv = v.begin(); iv != v.end(); ++iv)  
    cout << *iv << " ";  
    cout << endl;  
    cout << "-------------4--------------" << 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;  
    cout << "-------------5--------------" << endl;  
 
    //注意：pop_front()只适用于list和deque容器类型  
    v.pop_back(); //删除最后一个元素 
    for_each(v.begin(), v.end(), print);  
    cout << endl;  
    cout << "-------------6--------------" << endl;  
 
    //5. 查询  
    cout << v.front() << endl;  
    cout << v.back() << endl;  
    cout << "-------------7--------------" << endl;  
 
    //危险的做法，但一般我们就像访问数组那样操作就行,错误的，打印出来的有多出的元素 
    for (int i = 15; i < 25; i++)  
        cout << "Element " << i << " is " << v[i] << endl;  
    cout << "-------------8--------------" << 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;  
    cout << "-------------9--------------" << 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。  
    cout << "-------------10--------------" << endl; 
 
    return 0;  
} 
 
/* 
//执行结果 
# ./pp 
100 
10 
-------------1-------------- 
2 2 2 2 2 2 2 2 2 2 0 1 2 3 4 5 6 7 8 9  
20 
-------------2-------------- 
2 2 2 99 2 2 2 2 2 2 2 0 1 2 3 4 5 6 88 7 8 9  
9 8 7 88 6 5 4 3 2 1 0 2 2 2 2 2 2 2 99 2 2 2  
-------------3-------------- 
2 2 2 99 2 2 2 2 2 2 2 0 1 2 3 4 5 6 88 7 8 9  
-------------4-------------- 
2 2 2 2 2 2 2 2 2 2 0 1 2 3 4 5 6 88 7 8 9  
99 2 2 2 2 2 2 2 0 1 2 3 4 5 6 88 7 8 9  
-------------5-------------- 
99 2 2 2 2 2 2 2 0 1 2 3 4 5 6 88 7 8  
-------------6-------------- 
99 
8 
-------------7-------------- 
Element 15 is 88 
Element 16 is 7 
Element 17 is 8 
Element 18 is 9 
Element 19 is 7 
Element 20 is 8 
Element 21 is 9 
Element 22 is 0 
Element 23 is 0 
Element 24 is 0 
-------------8-------------- 
Element 15 is 88 
Element 16 is 7 
Element 17 is 8 
out_of_range at 18 
 
-------------9-------------- 
0 
-------------10-------------- 
 
*/