fig20_29.cpp

经典vc教程的例子程序

// Fig. 20.29: fig20_29.cpp
// Demonstrates Standard Library functions replace, replace_if
// replace_copy and replace_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, " " );

   // Replace 10s in v1 with 100
   vector< int > v1( a, a + SIZE );
   cout << "Vector v1 before replacing all 10s:\n";
   copy( v1.begin(), v1.end(), output );
   replace( v1.begin(), v1.end(), 10, 100 );
   cout << "\nVector v1 after replacing all 10s with 100s:\n";
   copy( v1.begin(), v1.end(), output );

   // copy from v2 to c1, replacing 10s with 100s
   vector< int > v2( a, a + SIZE );
   vector< int > c1( SIZE );
   cout << "\n\nVector v2 before replacing all 10s "
        << "and copying:\n";
   copy( v2.begin(), v2.end(), output );
   replace_copy( v2.begin(), v2.end(), 
                 c1.begin(), 10, 100 );
   cout << "\nVector c1 after replacing all 10s in v2:\n";
   copy( c1.begin(), c1.end(), output );

   // Replace values greater than 9 in v3 with 100
   vector< int > v3( a, a + SIZE );
   cout << "\n\nVector v3 before replacing values greater"
        << " than 9:\n";
   copy( v3.begin(), v3.end(), output );
   replace_if( v3.begin(), v3.end(), greater9, 100 );
   cout << "\nVector v3 after replacing all values greater"
        << "\nthan 9 with 100s:\n";
   copy( v3.begin(), v3.end(), output );

   // Copy v4 to c2, replacing elements greater than 9 with 100
   vector< int > v4( a, a + SIZE );
   vector< int > c2( SIZE );
   cout << "\n\nVector v4 before replacing all values greater"
        << "\nthan 9 and copying:\n";
   copy( v4.begin(), v4.end(), output );
   replace_copy_if( v4.begin(), v4.end(), c2.begin(), 
                    greater9, 100 );
   cout << "\nVector c2 after replacing all values greater"
        << "\nthan 9 in v4:\n";
   copy( c2.begin(), c2.end(), output );

   cout << endl;
   return 0;
}

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