1 // alg_equal.cpp
2 // compile with: /EHsc
3 #include <vector>
4 #include <algorithm>
5 #include <iostream>
6
7 // Return whether second element is twice the first
8 bool twice ( int elem1, int elem2 )
9 {
10 return elem1 * 2 == elem2;
11 }
12
13 int main( )
14 {
15 using namespace std;
16 vector <int> v1, v2, v3;
17 vector <int>::iterator Iter1, Iter2, Iter3;
18
19 int i;
20 for ( i = 0 ; i <= 5 ; i++ )
21 {
22 v1.push_back( 5 * i );
23 }
24
25 int ii;
26 for ( ii = 0 ; ii <= 5 ; ii++ )
27 {
28 v2.push_back( 5 * ii );
29 }
30
31 int iii;
32 for ( iii = 0 ; iii <= 5 ; iii++ )
33 {
34 v3.push_back( 10 * iii );
35 }
36
37 cout << "v1 = ( " ;
38 for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
39 cout << *Iter1 << " ";
40 cout << ")" << endl;
41
42 cout << "v2 = ( " ;
43 for ( Iter2 = v2.begin( ) ; Iter2 != v2.end( ) ; Iter2++ )
44 cout << *Iter2 << " ";
45 cout << ")" << endl;
46
47 cout << "v3 = ( " ;
48 for ( Iter3 = v3.begin( ) ; Iter3 != v3.end( ) ; Iter3++ )
49 cout << *Iter3 << " ";
50 cout << ")" << endl;
51
52 // Testing v1 and v2 for equality under identity
53 bool b;
54 b = equal( v1.begin( ), v1.end( ), v2.begin( ) );
55
56 if ( b )
57 cout << "The vectors v1 and v2 are equal under equality."
58 << endl;
59 else
60 cout << "The vectors v1 and v2 are not equal under equality."
61 << endl;
62
63 // Testing v1 and v3 for equality under identity
64 bool c;
65 c = equal( v1.begin( ), v1.end( ), v3.begin( ) );
66
67 if ( c )
68 cout << "The vectors v1 and v3 are equal under equality."
69 << endl;
70 else
71 cout << "The vectors v1 and v3 are not equal under equality."
72 << endl;
73
74 // Testing v1 and v3 for equality under twice
75 bool d;
76 d = equal( v1.begin( ), v1.end( ), v3.begin( ), twice );
77
78 if ( d )
79 cout << "The vectors v1 and v3 are equal under twice."
80 << endl;
81 else
82 cout << "The vectors v1 and v3 are not equal under twice."
83 << endl;
84 }
85
86 /*
87 Output
88
89 v1 = ( 0 5 10 15 20 25 )
90 v2 = ( 0 5 10 15 20 25 )
91 v3 = ( 0 10 20 30 40 50 )
92 The vectors v1 and v2 are equal under equality.
93 The vectors v1 and v3 are not equal under equality.
94 The vectors v1 and v3 are equal under twice.
95 */
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