Reverse

#include <vector>
#include <algorithm>
#include <iostream>
#include <sys/time.h>
#include <cstdlib>
 
using namespace std;

int main()
{
  timeval t1, t2;
  double elapsedTime;
  std::vector<long> v(100000000); // vector for 100000000 elements
  std::generate(v.begin(), v.end(), rand); // filling with random numbers
  // start timer
  gettimeofday(&t1, NULL);
  std::reverse(v.begin(),v.end());  // REVERSE HERE
  // stop timer
  gettimeofday(&t2, NULL);
  // compute and print the elapsed time in millisec
  elapsedTime = (t2.tv_sec - t1.tv_sec) * 1000.0;      // sec to ms
  elapsedTime += (t2.tv_usec - t1.tv_usec) / 1000.0;   // us to ms
  std::cout << "reverse -> " << elapsedTime << " ms.\n";
  return 0;
}