reverse http://www.cplusplus.com/reference/algorithm/reverse/

// 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;
}