CHAPTER10-19.cpp
上传用户:fjc899
上传日期:2007-07-03
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文件大小:2k
- //文件名:CHAPTER10-19.cpp
- #include <map>
- #include <iostream>
- #if _MSC_VER > 1020 // if VC++ version is > 4.2
- using namespace std; // std c++ libs implemented in std
- #endif
- void main( )
- {
- map <int, int> m1, m2, m3;
- map <int, int> :: iterator pIter, Iter1, Iter2;
- int i, n;
- typedef pair <int, int> Int_Pair;
- for ( i = 1 ; i < 5 ; i++ )
- {
- m1.insert ( Int_Pair ( i, i ) );
- m2.insert ( Int_Pair ( i, i*i ) );
- m3.insert ( Int_Pair ( i, i-1 ) );
- }
- // The 1st member function removes an element at a given position
- Iter1 = ++m1.begin( );
- m1.erase( Iter1 );
- cout << "After the 2nd element is deleted, the map m1 is:" ;
- for ( pIter = m1.begin( ) ; pIter != m1.end( ) ; pIter++ )
- cout << " " << pIter -> second;
- cout << "." << endl;
- // The 2nd member function removes elements in the range [_First, _Last)
- Iter1 = ++m2.begin( );
- Iter2 = --m2.end( );
- m2.erase( Iter1, Iter2 );
- cout << "After the middle two elements are deleted,"<< " the map m2 is:" ;
- for ( pIter = m2.begin( ) ; pIter != m2.end( ) ; pIter++ )
- cout << " " << pIter -> second;
- cout << "." << endl;
- // The 3rd member function removes elements with a given _Key
- n = m3.erase( 2 );
- cout << "After the element with a key of 2 is deleted,n"<< "the map m3 is:" ;
- for ( pIter = m3.begin( ) ; pIter != m3.end( ) ; pIter++ )
- cout << " " << pIter -> second;
- cout << "." << endl;
- // The 3rd member function returns the number of elements removed
- cout << "The number of elements removed from m3 is: "<< n << "." << endl;
- // The dereferenced iterator can also be used to specify a key
- Iter1 = ++m3.begin( );
- m3.erase( Iter1 );
- cout << "After another element with a key equal to that"<< endl;
- cout << "of the 2nd element is deleted, "<< "the map m3 is:" ;
- for ( pIter = m3.begin( ) ; pIter != m3.end( ) ; pIter++ )
- cout << " " << pIter -> second;
- cout << "." << endl;
- }