prev_permutation

template <class BidirectionalIterator>
  bool prev_permutation (BidirectionalIterator first,
                         BidirectionalIterator last );

template <class BidirectionalIterator, class Compare>
  bool prev_permutation (BidirectionalIterator first,
                         BidirectionalIterator last, Compare comp);

Transform range to previous permutation

Parameters

first, last

Bidirectional iterators to the initial and final positions of the sequence. The range used is [first,last), which contains all the elements between first and last, including the element pointed by first but not the element pointed by last.

comp

Comparison function object that, taking two values of the same type than those contained in the range, returns true if the first argument is to be considered less than the second argument.

Return value

Example

// prev_permutation
#include <iostream>
#include <algorithm>
using namespace std;
int main () {
  int myints[] = {1,2,3};
  cout << "The 3! possible permutations with 3 elements:\n";
  sort (myints,myints+3);
  reverse (myints,myints+3);
  do {
    cout << myints[0] << " " << myints[1] << " " << myints[2] << endl;
  } while ( prev_permutation (myints,myints+3) );
  return 0;
}

3 2 1
3 1 2
2 3 1
2 1 3
1 3 2
1 2 3

Complexity

See also