chapter11-21.cpp

C++STL程序员开发指南

//文件名:CHAPTER11-21.cpp
#include <vector>
#include <list>
#include <algorithm>
#include <functional>      // For greater<int>( )
#include <iostream>
// Return whether first element is greater than the second
bool UDgreater ( int elem1, int elem2 )
{   return elem1 > elem2;}
int main( )
{
   using namespace std;
   vector <int> v1,v2;
   vector <int>::iterator Iter1, Iter2;
   list <int> L1;
   L1.push_back( 60 );
   L1.push_back( 50 );
   L1.push_back( 20 );
   L1.push_back( 30 );
   L1.push_back( 40 );
   L1.push_back( 10 );
   int i;
   for ( i = 0 ; i <= 5 ; i++ )
   {      v1.push_back( 2 * i );   }
   int ii;
   for ( ii = 0 ; ii <= 5 ; ii++ )
   {      v1.push_back( 2 * ii + 1 );   }
   cout << "Original vector v1 = ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")" << endl;
   sort( v1.begin( ), v1.end( ) );
   cout << "Sorted vector v1 = ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")" << endl;
   // To sort in descending order. specify binary predicate
   sort( v1.begin( ), v1.end( ), greater<int>( ) );
   cout << "Resorted (greater) vector v1 = ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")" << endl;
   // A user-defined (UD) binary predicate can also be used
   sort( v1.begin( ), v1.end( ), UDgreater );
   cout << "Resorted (UDgreater) vector v1 = ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")" << endl;
// To partially sort in descending order, specify binary predicate
   partial_sort(v1.begin( ), v1.begin( ) + 4, v1.end( ), greater<int>( ) );
   cout << "Partially resorted (greater) vector:\n v1 = ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")" << endl;
   // A user-defined (UD) binary predicate can also be used
   partial_sort(v1.begin( ), v1.begin( ) + 8, v1.end( ), 
 UDgreater );
   cout << "Partially resorted (UDgreater) vector:\n v1 = ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")" << endl;
// Copying a partially sorted copy of L1 into v2
   for ( ii = 0 ; ii <= 9 ; ii++ )
   {      v2.push_back( ii );   }
   random_shuffle( v2.begin( ), v2.end( ) );
   vector <int>::iterator result2;
   result2 = partial_sort_copy (L1.begin( ), L1.end( ), v2.begin( ), 
          v2.begin( ) + 6, greater<int>( ) );
   cout << "List L1 into Vector v2 = ( " ;
   for ( Iter2 = v2.begin( ) ; Iter2 != v2.end( ) ; Iter2++ )
      cout << *Iter2 << " ";
   cout << ")" << endl;
   cout << "The first v2 element one position beyond"
        << "\n the last L 1 element inserted was " << *result2 
        << "." << endl;
}