chapter11-3.cpp

C++STL程序员开发指南

//文件名:CHAPTER11-3.cpp
#include <vector>
#include <algorithm>
#include <iostream>
// Return whether second element is twice the first
bool twice ( int elem1, int elem2 )
{   return elem1 * 2 == elem2;}
int main( )
{
   using namespace std;
   vector <int> v1, v2, v3;
   vector <int>::iterator Iter1, Iter2, Iter3;
   int i;
   for ( i = 0 ; i <= 5 ; i++ ){v1.push_back( 5 * i );}
   int ii;
   for ( ii = 0 ; ii <= 5 ; ii++ ) {v2.push_back( 5 * ii );}
   int iii;
   for ( iii = 0 ; iii <= 5 ; iii++ ) {v3.push_back( 10 * iii );}
   cout << "v1 = ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ ) cout << *Iter1 << " ";
   cout << ")" << endl<< "v2 = ( " ;
   for ( Iter2 = v2.begin( ) ; Iter2 != v2.end( ) ; Iter2++ ) cout << *Iter2 << " ";
   cout << ")" << endl;
   cout << "v3 = ( " ;
   for ( Iter3 = v3.begin( ) ; Iter3 != v3.end( ) ; Iter3++ ) cout << *Iter3 << " ";
   cout << ")" << endl;
   // Testing v1 and v2 for equality under identity
   bool b;
   b = equal( v1.begin( ), v1.end( ), v2.begin( ) );
   if ( b ) cout << "The vectors v1 and v2 are equal under equality."<< endl;
   else cout << "The vectors v1 and v2 are not equal under equality."<< endl;
   // Testing v1 and v3 for equality under identity
   bool c;
   c = equal( v1.begin( ), v1.end( ), v3.begin( ) );
   if ( c ) cout << "The vectors v1 and v3 are equal under equality."<< endl;
   else cout << "The vectors v1 and v3 are not equal under equality."<< endl;
   // Testing v1 and v3 for equality under twice
   bool d;
   d = equal( v1.begin( ), v1.end( ), v3.begin( ), twice );
   if ( d ) cout << "The vectors v1 and v3 are equal under twice."<< endl;
   else cout << "The vectors v1 and v3 are not equal under twice."<< endl;
}