reverse
Reverses the order of the elements
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Definition
The reverse() algorithm is defined in the standard header <algorithm> and in the nonstandard backward-compatibility header <algo.h>.
Interface
#include <algorithm>
template < class BidirectionalIterator >
void reverse(
BidirectionalIterator first,
BidirectionalIterator last
);Parameters:
| Parameter | Description |
| first | A bidirectional iterator pointing to the position of the first element in the range within which the elements are being permuted |
| last | A bidirectional iterator pointing to the position one past the final element in the range within which the elements are being permuted |
Description
Reverse function reverses the order of the elements within a range.
Return Value
None.
Complexity
The complexity is linear; calls swap one half the length of range [first,last) times.
References
Example 1
Problem
This example of program illustrates the functionality of reverse() algorithm.
Workings
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
vector <int> v1;
vector <int>::iterator Iter1;
int i;
for ( i = 0 ; i <= 9 ; i++ )
v1.push_back( i );
cout <<"The original vector v1 is:\n ( " ;
for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
cout <<*Iter1<<" ";
cout <<")."<<endl;
// Reverse the elements in the vector
reverse (v1.begin( ), v1.end( ) );
cout <<"The modified vector v1 with values reversed is:\n ( " ;
for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
cout <<*Iter1<<" ";
cout <<")."<<endl;
return 0;
}Solution
Output:
The original vector v1 is:
( 0 1 2 3 4 5 6 7 8 9 ).
The modified vector v1 with values reversed is:
( 9 8 7 6 5 4 3 2 1 0 ).
References