Cycle through v in the reverse direction using a reverse_iterator. : vector iterator « vector « C++ Tutorial

1. C++ Tutorial
2. vector
3. vector iterator

#include <iostream>
#include <vector>

using namespace std;

void show(const char *msg, vector<int> vect);

int main() {

  // Declare a vector that has an initial capacity of 10.
  vector<int> v(10);

  for(unsigned i=0; i < v.size(); ++i) v[i] = i*i;

  // Create an empty vector and then assign it a sequence that is the reverse of v.
  vector<int> v3;
  v3.assign(v.rbegin(), v.rend());
  show("v3 contains the reverse of v: ", v3);

  // Show the size and capacity of v.
  cout << "Size of v is " << v.size() << ". The capacity is " << v.capacity() << ".\n";

  // Now, resize v.
  v.resize(20);
  cout << "After calling resize(20), the size of v is "
       << v.size() << " and the capacity is "
       << v.capacity() << ".\n";

  // Now, reserve space for 50 elements.
  v.reserve(50);
  cout << "After calling reserve(50), the size of v is "
       << v.size() << " and the capacity is "
       << v.capacity() << ".\n";

  return 0;
}

void show(const char *msg, vector<int> vect) {
  cout << msg << endl;
  for(unsigned i=0; i < vect.size(); ++i)
    cout << vect[i] << endl;
}