向量容器2

[cpp] // P96_example3.cpp : Defines the entry point for the console application.
//

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

void print(std::vector<int>);

int _tmain(int argc, _TCHAR* argv[])
{
    std::vector<int> vec;
    vec.push_back(1);
    vec.push_back(6);
    vec.push_back(6);
    vec.push_back(3);
    //删除vec数组中的所有6
    std::vector<int>::iterator itor1;
    std::vector<int>::iterator itor2;
    for(itor1 = vec.begin(); itor1 != vec.end(); itor1++)
    {
        if(6 == *itor1)
        {
            itor2 = itor1;
            vec.erase(itor2);   //删除指定位置的元素
        }
    }
    print(vec);
    return 0;
}

void print(std::vector<int> v)
{
    std::cout<<"vector size is: "<<v.size()<<std::endl;
    std::vector<int>::iterator p = v.begin();
    while(p != v.end())
    {
        std::cout<<*p<<std::endl;
        p++;
    }
}

// P96_example3.cpp : Defines the entry point for the console application.
//

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

void print(std::vector<int>);

int _tmain(int argc, _TCHAR* argv[])
{
std::vector<int> vec;
vec.push_back(1);
vec.push_back(6);
vec.push_back(6);
vec.push_back(3);
//删除vec数组中的所有6
std::vector<int>::iterator itor1;
std::vector<int>::iterator itor2;
for(itor1 = vec.begin(); itor1 != vec.end(); itor1++)
{
  if(6 == *itor1)
  {
   itor2 = itor1;
   vec.erase(itor2); //删除指定位置的元素
  }
}
print(vec);
return 0;
}

void print(std::vector<int> v)
{
std::cout<<"vector size is: "<<v.size()<<std::endl;
std::vector<int>::iterator p = v.begin();
while(p != v.end())
{
std::cout<<*p<<std::endl;
p++;
}
}

解析：

这是迭代器问题，只能删除第一个6，以后迭代器就失效了，不能删除之后的元素。

itor2 = itor1；这句说明两个迭代器是一样的。vec.erase(itor2)；等于vec.erase(itor1)；，这时指针已经指向下一个元素了。itor1++；又自增了，指向了下一个元素3，略过了第二个6。

答案：

修改方法1：使用vector模版里面的remove函数进行修改，代码如下：

[cpp] // P96_example3.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <iostream>
#include <vector>
<SPAN style="COLOR: #ff0000">#include <algorithm></SPAN>

void print(std::vector<int>);

int _tmain(int argc, _TCHAR* argv[])
{
    std::vector<int> vec;
    vec.push_back(1);
    vec.push_back(6);
    vec.push_back(6);
    vec.push_back(3);
    //删除vec数组中的所有6
    std::vector<int>::iterator itor1;
    std::vector<int>::iterator itor2;
    itor1 = vec.begin();
    <SPAN style="COLOR: #ff0000">vec.erase(std::remove(vec.begin(),vec.end(),6),vec.end());</SPAN>
    print(vec);
    return 0;
}

void print(std::vector<int> v)
{
    std::cout<<"vector size is: "<<v.size()<<std::endl;
    std::vector<int>::iterator p = v.begin();
    while(p != v.end())
    {
        std::cout<<*p<<std::endl;
        p++;
    }
}

// P96_example3.cpp : Defines the entry point for the console application.
//

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

void print(std::vector<int>);

int _tmain(int argc, _TCHAR* argv[])
{
std::vector<int> vec;
vec.push_back(1);
vec.push_back(6);
vec.push_back(6);
vec.push_back(3);
//删除vec数组中的所有6
std::vector<int>::iterator itor1;
std::vector<int>::iterator itor2;
itor1 = vec.begin();
vec.erase(std::remove(vec.begin(),vec.end(),6),vec.end());
print(vec);
return 0;
}

void print(std::vector<int> v)
{
std::cout<<"vector size is: "<<v.size()<<std::endl;
std::vector<int>::iterator p = v.begin();
while(p != v.end())
{
std::cout<<*p<<std::endl;
p++;
}
}
修改方法2：为了让其不略过第二个6，可以使itor1--，再回到原来的位置上。具体代码修改如下：

补充：软件开发 , C++ ,