C++编程语言中有一种叫做Vector的应用方法。
(1)vector< 类型 > 标识符 ;
(2)vector< 类型 > 标识符(最大容量)；
(3)vector< 类型 > 标识符（最大容量，初始所有值）；
(4) int i[4] = {12,3,4,5};
vector< 类型 > vi(i , i+2); //得到i索引值为3以后的值 ；
(5)vector< vector<int> > //vi定义2维的容器；记得一定要有空格，不然会报错
vector< int > line // 在使用的时候一定要首先将vi个行进行初始化;
for(int i = 0 ; i < 10 ; i ++)
{
vector.push_back(line);
} /// 个人认为使用vector定义二维数组很好，
因为是长度可以不预先确定。很好。
(6)C++ Vector排序
vector< int > vi ;
vi.push_back(1);
vi.push_back(3);
vi.push_back(0);
sort(vi.begin() , vi.end()); /// /小到大
reverse(vi.begin(),vi.end()) /// 从大道小
(7)顺序访问
vector < int > vi ;
for( int i = 0 ; i < 10 ; i ++)
{ vector.push_back(i); }
for(int i = 0 ; i < 10 ; i ++) /// 第一种调用方法
{ cout <<vector[i] <<" " ; }
for(vector<int>::iterator it = vi.begin() ; it !=vi.end() ; it++) ///第二种调用方法
{ cout << *it << " " ; }
(8)寻找
vector < int > vi ;
for( int i = 0 ; i < 10 ; i ++)
{ vector.push_back(i); }
vector < int >::interator it = find(vi.begin() , vi.end,3) ;
cout << *it << endl ; ///返回容器内找到值的位置。
(9)使用数组对C++ Vector进行初始化
int i[10] ={1,2,3,4,5,6,7,78,8} ; ///第一种
vector<int> vi(i+1,i+3); ///从第2个元素到第三个元素
for(vector <int>::interator it = vi.begin() ; it != vi.end() ; it++)
{ cout << *it <<" " ; }
(10) 结构体类型
struct temp
{
public : string str ;
public : int id ;
};tmp
int main()
{
vector <temp> t ;
temp w1 ;
w1.str = "Hellowor" ;
w1.id = 1 ;
t.push_back(t1);
cout << w1.str << "," <<w1.id <<endl ;
return 0 ;
}
vector::push_back
public member function
void push_back ( const T& x );
Add element at the end
Adds a new element at the end of the vector,after its current last element. The content of this new element is initializedto a copy of x.
Thiseffectively increases the vector size by
one, which causes a reallocation of the internalallocated storage if the vector size was
equal to the vector capacitybefore the call. Reallocations invalidate allpreviously
obtained iterators, references and pointers.
Parameters
x
Value to be copied to the new element.
T is the first template parameter (the type of theelements stored in the vector).
Return value
none
If areallocation happens, it is performed using Allocator::allocate(), which may throw exceptions
(for thedefault allocator, bad_alloc is
thrown if the allocation request does notsucceed).
Example
//vector::push_back
#include<iostream>
#include<vector>
intmain ()
{
std::vector<int>myvector;
int myint;
std::cout << "Pleaseenter some integers (enter 0 to end):\n";
do {
std::cin >> myint;
myvector.push_back (myint);
} while (myint);
std::cout << "myvector stores" <<int(myvector.size()) << "numbers.\n";
return 0;
}
The example uses push_back to add a new element to the vector each time a new integeris read.
Complexity
Constant (amortized time, reallocation mayhappen).
See also
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Delete last element (public member function) |
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Insert elements (public member function) |
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