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  • vector-end

    2018-04-16 09:55:44
    //////////////////////////////////////...// vector-end #include <iostream> #include <vector> #include <iterator> #include <numeric> using name...
    
    //      2018/04/16 9:46:45
    //      vector-end
    
    #include <iostream>
    #include <vector>
    #include <iterator>
    #include <numeric>
    
    using namespace std;
    
    int main(){
        vector<int> v(5);
        iota(v.begin(),v.end(), 1);
    
        vector<int>::iterator it = v.begin();
        while (it != v.end()){
            cout << *(it++) << " ";
        }
        cout << endl;
    
        // last element of the vector
        it = v.end() - 1;
        cout << *it << endl;
        return 0;
    }
    
    /*
    OUTPUT:
        1 2 3 4 5
        5
    */ 
    展开全文
  • vector::empty // vector::empty #include #include using namespace std; int main () { vector myvector; int sum (0); for(int i=1;i;i++) myvector.push_back(i); while (!myvector.empty())

    vector::empty


    // vector::empty
    #include <iostream>
    #include <vector>
    using namespace std;
    int main ()
    {
      vector<int> myvector;
      int sum (0);
      for(int i=1;i<=10;i++) myvector.push_back(i);
      while (!myvector.empty())
      {
         sum += myvector.back();
         myvector.pop_back();
      }
      cout << "total: " << sum << '\n';  //输出 total: 55 
    
      return 0;
    }

    vector::end


    // vector::begin/end
    #include <iostream>
    #include <vector>
    using namespace std;
    int main ()
    {
       vector<int> myvector;
      for (int i=1; i<=5; i++) myvector.push_back(i);
      
      vector<int>::iterator it; 
      
      cout << "myvector contains:";
      for ( it = myvector.begin() ; it != myvector.end(); ++it)
        cout << ' ' << *it;
        cout << '\n';
      return 0;
    }
    //Output:
    //myvector contains: 1 2 3 4 5
    

    vector::erase


    // erasing from vector
    #include <iostream>
    #include <vector>
    using namespace std;
    int main ()
    {
        vector<int> myvector;
      // set some values (from 1 to 10)
      for (int i=1; i<=10; i++) myvector.push_back(i);
    
      // erase the 6th element
      myvector.erase (myvector.begin()+5);
    
      // erase the first 3 elements:
      myvector.erase (myvector.begin(),myvector.begin()+3);
    
       cout << "myvector contains:";
      for (unsigned i=0; i<myvector.size(); ++i)
        cout << ' ' << myvector[i];
        cout << '\n';
    
      return 0;
    }
    
    //Output:
    //myvector contains: 4 5 7 8 9 10
    




    展开全文
  • vector::end( )与vector::back( )

    千次阅读 2016-12-01 12:13:32
    vector::end( )与vector::back( ) 错误:vector iterator not dereferencable

    vector::end( )返回的是vector最后一个元素后的”结束元素“

    vector::back( )返回的是vector最后一个元素

    类比字符串,end( )返回的是’\0’,back( )返回的是字符串的最后一个字符

    如果试图对vector::end( )返回的元素(结束元素)进行操作,将导致如下错误:

    vector iterator not dereferencable

    下面详细介绍两个函数并举例说明——


    vector::end

    Returns an iterator referring to the past-the-end element in the vector container.

    The past-the-end element is the theoretical element that would follow the last element in the vector. It does not point to any element, and thus shall not be dereferenced.

    Because the ranges used by functions of the standard library do not include the element pointed by their closing iterator, this function is often used in combination with vector::begin to specify a range including all the elements in the container.

    If the container is empty, this function returns the same as vector::begin.

    Example

    // vector::begin/end
    #include <iostream>
    #include <vector>
    using namespace std;
    
    int main ()
    {
      vector<int> myvector;
      for (int i=1; i<=5; i++) myvector.push_back(i);
    
      cout << "myvector contains:";
      for (vector<int>::iterator it = myvector.begin() ; it != myvector.end(); ++it){
        cout << ' ' << *it;
      }
      cout << '\n';
    
      return 0;
    }

    Output

    myvector contains: 1 2 3 4 5

    vector::back

    Returns a reference to the last element in the vector.

    Unlike member vector::end, which returns an iterator just past this element, this function returns a direct reference.

    Calling this function on an empty container causes undefined behavior.

    Example

    // vector::back
    #include <iostream>
    #include <vector>
    using namespace std;
    
    int main ()
    {
      vector<int> myvector;
    
      myvector.push_back(10);
    
      while (myvector.back() != 0)
      {
        myvector.push_back ( myvector.back() -1 );
      }
    
      cout << "myvector contains:";
      for (unsigned i=0; i<myvector.size() ; i++){
        cout << ' ' << myvector[i];
      }
      cout << '\n';
    
      return 0;
    }

    Output

    myvector contains: 10 9 8 7 6 5 4 3 2 1 0
    展开全文
  • vector end()的返回值

    千次阅读 2019-06-29 19:08:14
    i 的地址和end 的地址差了4,刚好是 int 4个字节的大小,说明end 在 i 后面一个单位 (也扩充一下,vector 的物理内存其实是连续的) 上图是i 做了自加运算往后推了一位之后的结果,地址和end 一样了! 所以,遍历...

    end()的返回值

    begin()返回的是第一个元素的迭代器,但是end()返回的却是末尾元素再下一个元素的迭代器,下面进入调试界面详细了解一下:
    在这里插入图片描述

    i 的地址和end 的地址差了4,刚好是 int 4个字节的大小,说明end 在 i 后面一个单位 (也扩充一下,vector 的物理内存其实是连续的)
    在这里插入图片描述

    上图是i 做了自加运算往后推了一位之后的结果,地址和end 一样了!

    所以,遍历容器的时候,限制条件应为

        i<A.end();//小于
    

    这里附上上面的代码,大家可以自行调试:

    int main()
    {
        vector <int> A;
        A.push_back(1);
        vector<int>::iterator i=A.begin();
        vector<int>::iterator j=A.end();
        for(;i<A.end();)
        {
            i++;
            if(i==j)break;
        }
        return 0;
    }
    
    展开全文
  • <div><p>I am trying to parse the vector tile end points but the results I get http://localhost:3001/services/postgis/pois/geom/vector-tiles/{z}/{x}/{y}.json <p>are not readable. I can't open ...
  • stl vector 函数 C ++ vector :: end()函数 (C++ vector::end() function) vector::end() is a library function of "vector" header, it can be used to get the last element of a vector. It returns an iterator...
  • Fix end() on ACE_Vector

    2020-12-29 12:31:04
    <div><p>It was based on the the base array, not the ... v.end(); ++i) { return 1; } return 0; } </int></ace></code></pre>该提问来源于开源项目:DOCGroup/ACE_TAO</p></div>
  • vector

    2021-02-27 13:29:55
    vector 1.定义 定义int型数组 例子 说明 vectora 默认初始化,a为空 ...vectorb(a) ...vectora(100) ...vectora(100,6) ...vectora(10,“null”) ...vectorvec(10,“hello”) ...vectorb(a.begin(),a.end
  • STL vector::end()

    千次阅读 2010-09-02 09:44:00
    标准模板库的容器最基本的三个函数 vector::begin(), vector::end(), vector::size() iterator = vector::end() 返回的不是指向最后一个元素,而是指向最后的结束符。--iterator才是指向最后一个元素。...
  • Vector

    2019-09-11 16:02:07
    关于标准库的一些总结: vector::back() Returns a reference to the last element in the vector. Unlike member vector::end, which returns an iterator just pa...
  • c++中cend end C ++ vector :: cend()函数 (C++ vector::cend() function) vector::cend() is a library function of "vector" header, it can be used to get the last element of a vector. It returns a const ...
  • STL库容器vector begin函数&end函数 begin()函数返回一个指向当前vector起始元素的迭代器,end()函数返回一个指向当前vector末尾元素的下一个位置的迭代器。vector<int> v(10,0); //定义一个长度为10,初值为0的...
  • vector.end() 指向的节点

    2013-09-21 08:57:00
    存储器vectorvector.end() 指向的是最后的结束符,而不是最后一个元素。 转载于:https://www.cnblogs.com/qingsunny/p/3330981.html

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