reverseiterators.cpp

C++高级编程这本书所附的源代码

#include <algorithm>
#include <vector>
#include <iostream>
#include <iterator>
using namespace std;

// Function template to populate a container of ints.
// The container must support push_back().
template<typename Container>
void populateContainer(Container& cont)
{
  int num;

  while (true) {
    cout << "Enter a number (0 to quit): ";
    cin >> num;
    if (num == 0) {
      break;
    }
    cont.push_back(num);
  }
}

int main(int argc, char** argv)
{
  vector<int> myVector;
  populateContainer(myVector);

  int num;
  cout << "Enter a number to find: ";
  cin >> num;

  vector<int>::iterator it1;
  vector<int>::reverse_iterator it2;
  it1 = find(myVector.begin(), myVector.end(), num);
  it2 = find(myVector.rbegin(), myVector.rend(), num);

  if (it1 != myVector.end()) {
    cout << "Found " << num << " at position " << it1 - myVector.begin()
	 << " going forward.\n";
    cout << "Found " << num << " at position "
	 << it2.base() - 1 - myVector.begin() << " going backward.\n";
  } else {
    cout << "Failed to find " << num << endl;
  }

  return (0);
}