C++ 容器對象vector和list 的使用

在<<c++ primer>>第四版Exercise Section 9.3.4 的Exercise 9.20 是這樣的一道題目：編寫程序判斷一個vector<int> 容器包含的元素是否與list<int> 容器完全相同。測試代碼如下：

#include "stdafx.h"
#include <iostream>
#include <string>
#include <list>
#include <deque>
#include <vector>


using namespace std;

int main()
{
    vector<int> vect;
    list<int> li;
    int vect_copy[] = {1,2,3,2,1,2,6};
    int li_copy[] = {2,4,6,54,7,0,2};
    vect.insert(vect.begin(),vect_copy, vect_copy+7);
    li.insert(li.begin(),li_copy,li_copy+7);

    if (vect.size() != li.size())
    {
        cout << "it is different." << endl;
        return 0;
    }

    for (vector<int>::iterator begin = vect.begin(); begin != vect.end(); ++begin)
    {
        bool flag = false;
        for (list<int>::iterator begin_li = li.begin(); begin_li != li.end(); ++begin_li)
        {
            if (*begin == *begin_li)
            {
                flag = true;
                continue;
            }
        }
        if (flag)
        {

        }
        else
        {
            cout << *begin << " in vect is not in the list " << endl;
        }
    }
    system("PAUSE");
    return 0;
}

 

 容器對象有一個Insert成員函數，是用於在容器中插入元素使用，第一個參數是插入的位置，是個迭代器，后面兩個參數是需要插入的元素迭代器開始和結尾。因為數組名是一個指針，因此這里也直接傳入了數組名。

另外，這里有兩個循環，分別遍歷vector和list.

 

獲取元素操作如下：

#include "stdafx.h"
#include <vector>
#include <iostream>


using namespace std;


int main()
{
    vector<int> vect;
    int arry[] = {1,2,3,21,34,90};
    vector<int> vect2;
    vect.insert(vect.begin(),arry,arry+6);
    cout << vect[0] << endl;
    cout << vect.front() << endl;
    cout << *vect.begin() << endl;
    cout << vect2[0] << endl;
    system("PAUSE");
    return 0;
}

這里需要留意的是，如果容器對象為空，則必須要先進行判斷，否則操作未定義。如上代碼是不能運行的。

 

 刪除元素的操作如下，這里的代碼分別刪除容器中的偶數和奇數。刪除后打印容器。

#include "stdafx.h"
#include <vector>
#include <iostream>
#include <algorithm>
#include <list>

using namespace std;

int main()
{
    int ia[] = {0,1,1,2,3,5,8,13,21,55,89};
    list<int> li;
    vector<int> vect;
    li.insert(li.begin(),ia,ia+11);
    vect.insert(vect.begin(),ia,ia+11);


    // to operate the list object.
    for (auto begin = li.begin(); begin != li.end();)
    {
        if ((*begin)%2 == 0)
        {
            begin = li.erase(begin);
            continue;
        }
        ++begin;
    }

    cout << "To print the list with odd number:" << endl;

    // print the list.
    for (auto begin = li.begin(); begin != li.end(); ++begin)
    {
        cout << *begin << endl;
    }


    // to operate vector
    for (vector<int>::iterator begin = vect.begin(); begin != vect.end();)
    {
        if (*begin % 2)
        {
            begin = vect.erase(begin);
            continue;
        }
        ++begin;
    }

    cout << "To print the vector with with even number:" << endl;
    for (vector<int>::iterator begin = vect.begin(); begin != vect.end();++begin)
    {
        cout << *begin << endl;
    }

    system("PAUSE");
    return 0;
}

 

 

刪除特定元素操作如下：

#include "stdafx.h"
#include <vector>
#include <iostream>
#include <algorithm>
#include <list>
#include <string>

using namespace std;

int main()
{
    string arry[] = {"zhi","haha","heihei","hehe","huhu"};
    list<string> li;
    li.insert(li.begin(),arry,arry+sizeof(arry)/sizeof(*arry));
    list<string>::iterator ite = find(li.begin(),li.end(),"haha");
    li.erase(ite);

    for (list<string>::iterator begin = li.begin(); begin != li.end(); ++begin)
    {
        cout << *begin << endl;
    }
    system("PAUSE");
    return 0;
}

 

 

賦值操作如下，將一個vector中的元素拷貝到一個List 容器中。

#include "stdafx.h"
#include <vector>
#include <iostream>
#include <algorithm>
#include <list>
#include <string>

using namespace std;

int main()
{
    list<char*> li;
    vector<string> vect;
    
    char *listarry[] = {"hello","world","Li","Zhi"};
    string stringarry[] = {"heihei","haha","hehe","huhu"};
    li.insert(li.begin(), listarry, listarry+4);
    vect.insert(vect.begin(), stringarry, stringarry+4);

    cout << "The vector is : " << endl;
    for (vector<string>::iterator begin = vect.begin(); begin != vect.end(); ++begin)
    {
        cout << *begin << endl;
    }

    cout << "The list is : " << endl;
    for (list<char*>::iterator begin = li.begin(); begin != li.end(); ++begin)
    {
        cout << *begin << endl;
    }

    vect.assign(li.begin(),li.end());

    cout << "after update. The vector is : " << endl;
    for (vector<string>::iterator begin = vect.begin(); begin != vect.end(); ++begin)
    {
        cout << *begin << endl;
    }

    system("PAUSE");
    return 0;
}