search_n

搜索在指定数量的元素具有特定的值或关系对该指定的值由二进制谓词的第一subsequence。

template<class ForwardIterator1, class Diff2, class Type>
   ForwardIterator1 search_n(
      ForwardIterator1 _First1, 
      ForwardIterator1 _Last1,
      Diff2 _Count, 
      const Type& _Val
   );
template<class ForwardIterator1, class Diff2, class Type, class BinaryPredicate>
   ForwardIterator1 search_n(
      ForwardIterator1 _First1, 
      ForwardIterator1 _Last1,
      Diff2 _Count, 
      const Type& _Val,
      BinaryPredicate _Comp
   );

参数

• _First1
  解决仅向前迭代器的第一个元素的位置在要搜索的范围。

• _Last1
  解决仅向前的迭代器通过最终元素的位置一在要搜索的范围。

• _Count
  subsequence的范围内搜索。

• _Val
  元素的值序列中进行搜索。

• _Comp
  定义要满足条件的用户定义的谓词函数对象，如果两个组件要执行视为等效的。 二进制谓词采用两个参数并返回 true ，在满足和 false，在未满足。

返回值

解决仅向前迭代器的第一subsequence的第一个元素的位置二进制谓词实际上是等效的指定与指定的顺序或。

备注

用于的 operator== 确定在元素和指定值之间的匹配必须实施在其操作数之间的等效性关系。

引用的范围必须是有效的;所有指针必须dereferenceable，并在该序列中最后位置以访问按增量。

复杂是线性有关要搜索的大小。

示例

// alg_search_n.cpp
// compile with: /EHsc
#include <vector>
#include <list>
#include <algorithm>
#include <iostream>

// Return whether second element is 1/2 of the first
bool one_half ( int elem1, int elem2 )
{
   return elem1 == 2 * elem2;
}

int main( ) 
{
   using namespace std;
   vector <int> v1, v2;
   vector <int>::iterator Iter1;

   int i;
   for ( i = 0 ; i <= 5 ; i++ )
   {
      v1.push_back( 5 * i );
   }

   for ( i = 0 ; i <= 2 ; i++ )
   {
      v1.push_back( 5  );
   }

   for ( i = 0 ; i <= 5 ; i++ )
   {
      v1.push_back( 5 * i );
   }

   for ( i = 0 ; i <= 2 ; i++ )
   {
      v1.push_back( 10  );
   }

   cout << "Vector v1 = ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")" << endl;

   // Searching v1 for first match to (5 5 5) under identity
   vector <int>::iterator result1;
   result1 = search_n ( v1.begin( ), v1.end( ), 3, 5 );

   if ( result1 == v1.end( ) )
      cout << "There is no match for a sequence ( 5 5 5 ) in v1."
           << endl;
   else
      cout << "There is at least one match of a sequence ( 5 5 5 )"
           << "\n in v1 and the first one begins at "
           << "position "<< result1 - v1.begin( ) << "." << endl;

   // Searching v1 for first match to (5 5 5) under one_half
   vector <int>::iterator result2;
   result2 = search_n (v1.begin( ), v1.end( ), 3, 5, one_half );

   if ( result2 == v1.end( ) )
      cout << "There is no match for a sequence ( 5 5 5 ) in v1"
           << " under the equivalence predicate one_half." << endl;
   else
      cout << "There is a match of a sequence ( 5 5 5 ) "
           << "under the equivalence\n predicate one_half "
           << "in v1 and the first one begins at "
           << "position "<< result2 - v1.begin( ) << "." << endl;
}

要求

标头: <algorithm>

命名空间: std

请参见

参考

标准模板库