fig20_28.cpp

经典vc教程的例子程序

// Fig. 20.28: fig20_28.cpp
// Demonstrates Standard Library functions remove, remove_if
// remove_copy and remove_copy_if
#include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

bool greater9( int );

int main()
{ 
   const int SIZE = 10;
   int a[ SIZE ] = { 10, 2, 10, 4, 16, 6, 14, 8, 12, 10 };
   ostream_iterator< int > output( cout, " " );

   // Remove 10 from v
   vector< int > v( a, a + SIZE );
   vector< int >::iterator newLastElement;
   cout << "Vector v before removing all 10s:\n";
   copy( v.begin(), v.end(), output );
   newLastElement = remove( v.begin(), v.end(), 10 );
   cout << "\nVector v after removing all 10s:\n";
   copy( v.begin(), newLastElement, output );

   // Copy from v2 to c, removing 10s
   vector< int > v2( a, a + SIZE );
   vector< int > c( SIZE, 0 );
   cout << "\n\nVector v2 before removing all 10s "
        << "and copying:\n";
   copy( v2.begin(), v2.end(), output );
   remove_copy( v2.begin(), v2.end(), c.begin(), 10 );
   cout << "\nVector c after removing all 10s from v2:\n";
   copy( c.begin(), c.end(), output );

   // Remove elements greater than 9 from v3
   vector< int > v3( a, a + SIZE );
   cout << "\n\nVector v3 before removing all elements"
        << "\ngreater than 9:\n";
   copy( v3.begin(), v3.end(), output );
   newLastElement = remove_if( v3.begin(), v3.end(), 
                               greater9 );
   cout << "\nVector v3 after removing all elements"
        << "\ngreater than 9:\n";
   copy( v3.begin(), newLastElement, output );

   // Copy elements from v4 to c, 
   // removing elements greater than 9
   vector< int > v4( a, a + SIZE );
   vector< int > c2( SIZE, 0 );
   cout << "\n\nVector v4 before removing all elements"
        << "\ngreater than 9 and copying:\n";
   copy( v4.begin(), v4.end(), output );
   remove_copy_if( v4.begin(), v4.end(), 
                   c2.begin(), greater9 );
   cout << "\nVector c2 after removing all elements"
        << "\ngreater than 9 from v4:\n";
   copy( c2.begin(), c2.end(), output );

   cout << endl;
   return 0;
}

bool greater9( int x )
{
   return x > 9;
}