min

Compara dos objetos y devuelve el menor de los dos, donde el criterio de ordenación se puede especificar por un predicado binario.

template<class Type>
   const Type& min(
      const Type& _Left, 
      const Type& _Right
   );
template<class Type, class Pr>
   const Type& min(
      const Type& _Left, 
      const Type& _Right,
      BinaryPredicate _Comp
   );

Parámetros

• _Left
  El primero de los dos objetos comparados.

• _Right
  El segundo de los dos objetos comparados.

• _Comp
  un predicado binario utilizado para comparar los dos objetos.

Valor devuelto

Menos de los dos objetos a menos que cualquier menor, en cuyo caso devuelve el primero de los dos objetos.

Comentarios

El algoritmo de minuto es poco habitual en tener objetos pasados como parámetros.La mayoría de los algoritmos de biblioteca de plantillas estándar funcionan en un intervalo de elementos cuya posición es especificada por los iteradores pasados como parámetros.

Ejemplo

// alg_min.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( )
{
   // Comparing integers directly using the min algorithm with
   // binary predicate mod_lesser & with default less than
   int a = 6, b = -7, c = 7 ;
   const int& result1 = min ( a, b, mod_lesser );
   const int& result2 = min ( b, c );

   cout << "The mod_lesser of the integers 6 & -7 is: " 
        << result1 << "." << endl;
   cout << "The lesser of the integers -7 & 7 is: " 
        << result2 << "." << endl;
   cout << endl;

   // Comparing set containers with elements of type CInt 
   // using the min algorithm
   CInt c1 = 1, c2 = 2, c3 = 3;
   set<CInt> s1, s2, s3;
   set<CInt>::iterator s1_Iter, s2_Iter, s3_Iter;
   
   s1.insert ( c1 );
   s1.insert ( c2 );
   s2.insert ( c2 );
   s2.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;

   cout << "s2 = (";
   for ( s2_Iter = s2.begin( ); s2_Iter != --s2.end( ); s2_Iter++ )
      cout << " " << *s2_Iter << ",";
   s2_Iter = --s2.end( );
   cout << " " << *s2_Iter << " )." << endl;

   s3 = min ( s1, s2 );
   cout << "s3 = min ( s1, s2 ) = (";
   for ( s3_Iter = s3.begin( ); s3_Iter != --s3.end( ); s3_Iter++ )
      cout << " " << *s3_Iter << ",";
   s3_Iter = --s3.end( );
   cout << " " << *s3_Iter << " )." << endl << endl;

   // Comparing vectors with integer elements using min algorithm
   vector <int> v1, v2, v3, v4, v5;
   vector <int>::iterator Iter1, Iter2, Iter3, Iter4, Iter5;

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

   int ii;
   for ( ii = 0 ; ii <= 2 ; ii++ )
   {
      v2.push_back( ii );
   }

   int iii;
   for ( iii = 0 ; iii <= 2 ; iii++ )
   {
      v3.push_back( 2 * iii );
   }
   
   cout << "Vector v1 is ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")." << endl;

   cout << "Vector v2 is ( " ;
   for ( Iter2 = v2.begin( ) ; Iter2 != v2.end( ) ; Iter2++ )
      cout << *Iter2 << " ";
   cout << ")." << endl;
   
   cout << "Vector v3 is ( " ;
   for ( Iter3 = v3.begin( ) ; Iter3 != v3.end( ) ; Iter3++ )
      cout << *Iter3 << " ";
   cout << ")." << endl;

   v4 = min ( v1, v2 );
   v5 = min ( v1, v3 );

   cout << "Vector v4 = min ( v1,v2 ) is ( " ;
   for ( Iter4 = v4.begin( ) ; Iter4 != v4.end( ) ; Iter4++ )
      cout << *Iter4 << " ";
   cout << ")." << endl;

   cout << "Vector v5 = min ( v1,v3 ) is ( " ;
   for ( Iter5 = v5.begin( ) ; Iter5 != v5.end( ) ; Iter5++ )
      cout << *Iter5 << " ";
   cout << ")." << endl;
}

Requisitos

encabezado: <algoritmo>

espacio de nombres: std

Vea también

Referencia

Biblioteca de plantillas estándar