min_element

Finds the first occurrence of smallest element in a specified range where the ordering criterion may be specified by a binary predicate.

template<class ForwardIterator> 
   ForwardIterator min_element( 
      ForwardIterator first,  
      ForwardIterator last 
   ); 
template<class ForwardIterator, class BinaryPredicate> 
   ForwardIterator min_element( 
      ForwardIterator first,  
      ForwardIterator last,
      BinaryPredicate comp 
   );

매개 변수

• first
  A forward iterator addressing the position of the first element in the range to be searched for the smallest element.

• last
  A forward iterator addressing the position one past the final element in the range to be searched for the smallest element.

• comp
  한 요소가 다른 요소보다 큰 개념을 정의하는 사용자 정의 조건자 함수 개체입니다. 이진 술부는 두 개의 인수를 사용하고 첫 번째 요소가 두 번째 요소보다 작으면 true 을 반환해야 하고, 그렇지 않으면 false 를 반환합니다.

반환 값

A forward iterator addressing the position of the first occurrence of the smallest element in the range searched.

설명

참조된 범위는 유효해야 하며 모든 포인터는 역참조할 수 있어야 하고 각 시퀀스 내에서 마지막 위치는 처음부터 증분 만큼 접근할 수 있어야 합니다.

복잡도는 선형입니다: (last - first) – 1 비교는 비어 있지 않은 범위에 대해 필요 합니다.

예제

// alg_min_element.cpp
// compile with: /EHsc
#include <vector>
#include <set>
#include <algorithm>
#include <iostream>
#include <ostream>

using namespace std;
class CInt;
ostream& operator<<( ostream& osIn, const CInt& rhs );

class CInt
{
public:
   CInt( int n = 0 ) : m_nVal( n ){}
   CInt( const CInt& rhs ) : m_nVal( rhs.m_nVal ){}
   CInt& operator=( const CInt& rhs ) {m_nVal = 
   rhs.m_nVal; return *this;}
   bool operator<( const CInt& rhs ) const 
      {return ( m_nVal < rhs.m_nVal );}
   friend ostream& operator<<( ostream& osIn, const CInt& rhs );

private:
   int m_nVal;
};

inline ostream& operator<<( ostream& osIn, const CInt& rhs )
{
   osIn << "CInt( " << rhs.m_nVal << " )"; 
   return osIn;
}

// Return whether modulus of elem1 is less than modulus of elem2
bool mod_lesser ( int elem1, int elem2 )
{
   if ( elem1 < 0 ) 
      elem1 = - elem1;
   if ( elem2 < 0 ) 
      elem2 = - elem2;
   return elem1 < elem2;
};

int main()
{
   // Searching a set container with elements of type CInt 
   // for the minimum element 
   CInt c1 = 1, c2 = 2, c3 = -3;
   set<CInt> s1;
   set<CInt>::iterator s1_Iter, s1_R1_Iter, s1_R2_Iter;
   
   s1.insert ( c1 );
   s1.insert ( c2 );
   s1.insert ( c3 );

   cout << "s1 = (";
   for ( s1_Iter = s1.begin( ); s1_Iter != --s1.end( ); s1_Iter++ )
      cout << " " << *s1_Iter << ",";
   s1_Iter = --s1.end( );
   cout << " " << *s1_Iter << " )." << endl;

   s1_R1_Iter = min_element ( s1.begin ( ) , s1.end ( ) );

   cout << "The smallest element in s1 is: " << *s1_R1_Iter << endl;
   cout << endl;

   // Searching a vector with elements of type int for the maximum
   // element under default less than & mod_lesser binary predicates
   vector <int> v1;
   vector <int>::iterator v1_Iter, v1_R1_Iter, v1_R2_Iter;

   int i;
   for ( i = 0 ; i <= 3 ; i++ )
   {
      v1.push_back( i );
   }

   int ii;
   for ( ii = 1 ; ii <= 4 ; ii++ )
   {
      v1.push_back( - 2 * ii );
   }
   
   cout << "Vector v1 is ( " ;
   for ( v1_Iter = v1.begin( ) ; v1_Iter != v1.end( ) ; v1_Iter++ )
      cout << *v1_Iter << " ";
   cout << ")." << endl;

   v1_R1_Iter = min_element ( v1.begin ( ) , v1.end ( ) );
   v1_R2_Iter = min_element ( v1.begin ( ) , v1.end ( ), mod_lesser);

   cout << "The smallest element in v1 is: " << *v1_R1_Iter << endl;
   cout << "The smallest element in v1 under the mod_lesser"
        << "\n binary predicate is: " << *v1_R2_Iter << endl;
}

요구 사항

헤더: <algorithm>

네임스페이스: std

참고 항목

참조

min_element(STL 샘플)

min_element의 Predicate 버전

표준 템플릿 라이브러리