C++/STL Algorithms Min Max/max
Call max() with special comparison function
/* 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.
*/
#include <algorithm>
#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
*/
Use max for char and integer
#include <iostream>
using std::cout;
using std::endl;
#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
*/
Using Custom Definitions of the Minimum and Maximum
#include <numeric>
#include <vector>
#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 );
}