find element in both array and vector using one myfind function

最新推荐文章于 2024-04-07 14:49:08 发布

原创最新推荐文章于 2024-04-07 14:49:08 发布 · 1.5k 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#vector #function #iterator #string #search #system

c++ 专栏收录该内容

29 篇文章

订阅专栏

本文介绍了一种在C++中利用指针而非迭代器进行数组或标准容器（如vector）内元素查找的方法。定义了通用的myfind函数，并通过示例展示了如何在字符串向量中查找特定字符串。

#include<iostream>
#include<vector>
#include<string>
using namespace std;

//find the begin and end pointer instead of iterator
//just for general function myfind defined blow.
//so you can search your element in both array and standard container .. vector

template <typename elemType>
inline const elemType* begin( const vector<elemType> &vec )
{
return vec.empty() ? 0 : &vec[0];
}

template <typename elemType>
inline const elemType* end( const vector<elemType> &vec )
{
       //make sure that the next address of the end of the vec
       //not &vec[vec.size()-1] but &vec[vec.size()]
       return vec.empty() ? 0 : &vec[vec.size()];
}

template <typename elemType>
const elemType* myfind( const elemType *first,
                        const elemType *last,
                        const elemType &value )
{
     if( !first || !last )
     {
         return 0;
     }
     for( ; first != last; ++first )
     {
          if( *first == value )
          {
              return first;
          }
     }
     return 0;
}

int main()
{
    vector<string> svec;
    svec.push_back("iloveyou");
    string iloveyou("iloveyou");

    // make sure that convert iterator to pointer to limit the arrange
    const string* result = myfind( begin( svec ), end(svec), iloveyou );
    cout << *result <<endl;
    system("pause");
    return 0;
}