next_permutation() and prev_permutation(). : next_permutation « STL Algorithms Helper « C++ Tutorial

1. C++ Tutorial
2. STL Algorithms Helper
3. next_permutation

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
  vector<char> v;
  unsigned i;

  for(i=0; i<3; i++) 
    v.push_back('A'+i);

  do {
    for(i=0; i < v.size(); i++){
      cout << v[i] << endl;
    }
  } while(next_permutation(v.begin(), v.end()));

  prev_permutation(v.begin(), v.end());
  
  do {
    for(i=0; i<v.size(); i++){
      cout << v[i] << endl;
    }
    
  } while(prev_permutation(v.begin(), v.end()));

  return 0;
}