Lesson N.6 of July 21, 2014

Added templates

mvlib10.zip

Example of use STL vector class

File example10.cc

:open:
 1/*
 2
 3  Some example of use of STL vector.
 4
 5*/
 6
 7#include <iostream>
 8#include <iomanip>
 9#include <vector>
10
11using namespace std ;
12
13typedef long int value_type ;
14
15
16int
17main() {
18  
19  vector<value_type> a, b(2) ;
20  
21  cout << "Size a = " << a.size() << '\n' ;
22  cout << "Size b = " << b.size() << '\n' ;
23
24  a.reserve(100) ;
25  for ( int i = 0 ; i < 10 ; ++i ) a.push_back(i*i) ;
26  
27  for ( int i = 0 ; i < 10 ; ++i )
28    cout << "a[ " << i << "] = " << a[i] << '\n';   
29
30  // access the element by iterators
31  //vector<int>::value_type ; // the type of the element of a vector<int>
32  //vector<int>::iterator ; // the type of a "pointer" of an element of a vector
33  for ( vector<value_type>::iterator it = a.begin() ; it != a.end() ; ++it )
34    cout << "a[ " << it-a.begin() << "] = " << *it << '\n';
35
36  a.clear() ;
37  a.push_back(23) ;
38  a.push_back(3) ;
39  a.push_back(-33) ;
40  a.push_back(2) ;
41  a.push_back(5) ;
42  a.push_back(-53) ;
43  a.push_back(21) ;
44  cout << "Size     of a = " << a.size() << '\n' ;
45  cout << "Capacity of a = " << a.capacity() << '\n' ;
46  cout << "a = " ;
47  for ( vector<value_type>::iterator it = a.begin() ; it != a.end() ; ++it )
48    cout << *it << ' ' ;
49  cout << '\n' ;
50  
51  sort(a.begin(),a.end()) ;
52  cout << "a (sorted) = " ;
53  for ( vector<value_type>::iterator it = a.begin() ; it != a.end() ; ++it )
54    cout << *it << ' ' ;
55  cout << '\n' ;
56
57  reverse(a.begin(),a.end()) ;
58  cout << "a (reversed) = " ;
59  for ( vector<value_type>::iterator it = a.begin() ; it != a.end() ; ++it )
60    cout << *it << ' ' ;
61  cout << '\n' ;
62
63  return 0 ;
64}