28 Algorithms library [algorithms]

28.7 Sorting and related operations [alg.sorting]

28.7.11 Permutation generators [alg.permutation.generators]

template<class BidirectionalIterator> bool next_permutation(BidirectionalIterator first, BidirectionalIterator last); template<class BidirectionalIterator, class Compare> bool next_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
Requires: BidirectionalIterator shall satisfy the requirements of ValueSwappable.
Effects: Takes a sequence defined by the range [first, last) and transforms it into the next permutation.
The next permutation is found by assuming that the set of all permutations is lexicographically sorted with respect to operator< or comp.
Returns: true if such a permutation exists.
Otherwise, it transforms the sequence into the smallest permutation, that is, the ascendingly sorted one, and returns false.
Complexity: At most (last - first) / 2 swaps.
template<class BidirectionalIterator> bool prev_permutation(BidirectionalIterator first, BidirectionalIterator last); template<class BidirectionalIterator, class Compare> bool prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
Requires: BidirectionalIterator shall satisfy the requirements of ValueSwappable.
Effects: Takes a sequence defined by the range [first, last) and transforms it into the previous permutation.
The previous permutation is found by assuming that the set of all permutations is lexicographically sorted with respect to operator< or comp.
Returns: true if such a permutation exists.
Otherwise, it transforms the sequence into the largest permutation, that is, the descendingly sorted one, and returns false.
Complexity: At most (last - first) / 2 swaps.