C++/STL Algorithms Min Max/max

Call max() with special comparison function

<source lang="cpp">

/* The following code example is taken from the book

* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/

1. include <algorithm>
2. include <iostream>

using namespace std; /* function that compares two pointers by comparing the values to which they po int

*/

bool int_ptr_less (int* a, int* b) {

   return *a < *b;

} int main() {

   int x = 17;
   int y = 42;
   int* px = &x;
   int* py = &y;
   int* pmax;
   // call max() with special comparison function
   pmax = max (px, py, int_ptr_less);
   cout << *pmax;
   //...

}

/* 

42

*/       
   
 </source>

Use max for char and integer

<source lang="cpp">

1. include <iostream>

using std::cout; using std::endl;

1. include <algorithm>

int main() {

  cout << "\nThe maximum of "G" and "Z" is: " << std::max( "G", "Z" );
  cout << "\nThe maximum of 12 and 7 is: " << std::max( 12, 7 );
  cout << endl; 
  return 0;

}

/* 

The maximum of "G" and "Z" is: Z The maximum of 12 and 7 is: 12

*/       
   
 </source>

Using Custom Definitions of the Minimum and Maximum

<source lang="cpp">

1. include <numeric>
2. include <vector>
3. include <iostream>

using namespace std; bool norm_less_than( const vector<double>& a,const vector<double>& b ); int main( ) {

  const double data1[] = { 1.77, 3.33, -0.44 };
  const double data2[] = { -1.99, -2.11, 4.33 };
  vector<double> v1( data1, data1+sizeof( data1 )/sizeof( double ) );
  vector<double> v2( data2, data2+sizeof( data2 )/sizeof( double ) );
  const vector<double>& min_vector = min( v1, v2, norm_less_than );
  const vector<double>& max_vector = max( v1, v2, norm_less_than );

} // returns true if the norm of a is < norm of b, false otherwise inline bool norm_less_than( const vector<double>& a,const vector<double>& b ) {

  return inner_product( a.begin(), a.end(), a.begin(), 0.0 )
       < inner_product( b.begin(), b.end(), b.begin(), 0.0 );

}

 </source>