T9的空間

菜菜的學習了一下STL的vector，做一下筆記感覺這個網站講得通俗易懂http://www.cppreference.com/cppvector/index.html 寫了一下測試code(待續)

Vectors contain contiguous elements stored as an array. Accessing members of a vector or appending elements can be done in constant time, whereas locating a specific value or inserting elements into the vector takes linear time.

Display all entries for C++ Vectors on one page, or view entries individually:

Vector constructors	create vectors and initialize them with some data
Vector operators	compare, assign, and access elements of a vector
assign	assign elements to a vector
at	returns an element at a specific location
back	returns a reference to last element of a vector
begin	returns an iterator to the beginning of the vector
capacity	returns the number of elements that the vector can hold
clear	removes all elements from the vector
empty	true if the vector has no elements
end	returns an iterator just past the last element of a vector
erase	removes elements from a vector
front	returns a reference to the first element of a vector
insert	inserts elements into the vector
max_size	returns the maximum number of elements that the vector can hold
pop_back	removes the last element of a vector
push_back	add an element to the end of the vector
rbegin	returns a reverse_iterator to the end of the vector
rend	returns a reverse_iterator to the beginning of the vector
reserve	sets the minimum capacity of the vector
resize	change the size of the vector
size	returns the number of items in the vector
swap	swap the contents of this vector with another

 1#include<vector>
 2#include<iostream>
 3#include<algorithm>
 4using namespace std;
 5void print(int a){cout<<a<<" ";}
 6int main()
 7{
 8    vector<int>v,v1;
 9    vector<int>::iterator iv1,iv2;
10    vector<int>v2;
11    v2.reserve(10);    
12    v.assign(10,2);
13    cout<<v2.capacity()<<endl;//capacity容量輸出為10
14    cout<<v2.size()<<endl;//大小輸出為1
15    int i;
16    for(i=0;i<7;i++)v2.push_back(i);
17    for_each(v2.begin(),v2.end(),print);
18    cout<<endl;
19    for(iv1=v2.begin();iv1!=v2.end();iv1++)
20        if(*iv1==3)break;
21    if(iv1!=v2.end())v2.insert(iv1,99);
22    for_each(v2.begin(),v2.end(),print);
23    cout<<endl;
24    if(iv1!=v2.end())v2.insert(iv1,5,99);
25    for_each(v2.begin(),v2.end(),print);
26    cout<<endl;
27    if(iv1!=v2.end())v2.insert(iv1,v.begin(),v.end());
28    for_each(v2.begin(),v2.end(),print);
29    cout<<endl;
30    cout<<v2.size()<<endl;
31    v2.erase(v2.begin());
32    cout<<v2.size()<<endl;
33    v2.erase(v2.begin(),v2.end());
34    for_each(v2.begin(),v2.end(),print);
35    iv1=v.begin();iv2=v.end();
36    cout<<v.begin()<<endl;
37    cout<<v.end()<<endl;
38    cout<<iv1<<endl;
39    cout<<iv2<<endl;
40//    for(i=0;i<15;i++)cout<<v[i]<<" ";
41//    cout<<endl;
42//    for(i=0;i<15;i++)cout<<v.at(i)<<" ";//at()函數更加安全；
43//    cout<<endl;
44    for_each(v.begin(),v.end(),print);
45    cout<<endl;
46//    v1.assign(v.begin(),v.end());
47//    v1.assign(iv1+2,iv2-2);
48//    for(i=0;i<10;i++)cout<<v1[i]<<' ';
49//    cout<<endl;
50    for(i=0;i<10;i++)v1.push_back(i);
51    for_each(v1.begin()+1,v1.end()-2,print);//輸出begin開始指向的數據，直到end指向的前一個數據
52    for_each(v1.begin(),v1.end(),print);
53    cout<<endl;
54    cout<<v1.back()<<endl;
55    cout<<v1.front()<<endl;
56    cout<<v1.size()<<endl;
57    v.clear();
58    cout<<v.size()<<endl;
59    for_each(v.begin(),v.end(),print);//已經clear，begin==end，不會有任何結果。
60    return 0;
61}
62
63
64
65//試了一下結構體,感覺自己簡直太水了，努力學習中！
66
67#include<iostream>
68#include<vector>
69using namespace std;
70typedef struct node{
71    int x;
72    int y;
73}node;
74ostream operator<<(ostream in,node a){
75    in<<a.x<<a.y<<endl;
76    return in;
77}
78int main()
79{
80    vector<node>v(10);
81    v[0].x=1;v[0].y=1;
82    vector<node>::iterator iv(v.begin());
83    cout<<v[0].x<<v[0].y<<endl;
84    cout<<*iv<<endl;
85    cout<<iv->x<<iv->y<<endl;
86    return 0;
87}