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reverse
function template
<algorithm>
template <class BidirectionalIterator>
void reverse ( BidirectionalIterator first, BidirectionalIterator last);
Reverse range
Reverses the order of the elements in the range [first,last).
The behavior of this function template is equivalent to:
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template <class BidirectionalIterator>
void reverse ( BidirectionalIterator first, BidirectionalIterator last)
{
while ((first!=last)&&(first!=--last))
swap (*first++,*last);
}
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Parameters
- first, last
- Bidirectional iterators to the initial and final positions of the sequence to be reversed. The range used is [first,last), which contains all the elements between first and last, including the element pointed by first but not the element pointed by last.
Return value
none
Example
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// reverse algorithm example
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main () {
vector<int> myvector;
vector<int>::iterator it;
// set some values:
for (int i=1; i<10; ++i) myvector.push_back(i); // 1 2 3 4 5 6 7 8 9
reverse(myvector.begin(),myvector.end()); // 9 8 7 6 5 4 3 2 1
// print out content:
cout << "myvector contains:";
for (it=myvector.begin(); it!=myvector.end(); ++it)
cout << " " << *it;
cout << endl;
return 0;
}
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Output:
myvector contains: 9 8 7 6 5 4 3 2 1
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Complexity
Linear: Calls swap one half the length of range [first,last) times.
See also
| rotate | Rotate elements in range (function template) |
| random_shuffle | Rearrange elements in range randomly (function template) |
| swap | Exchange values of two objects (function template) |
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