cppreference.com > C++ Algorithms > random_shuffle random_shuffle Syntax:
      #include <algorithm>
      void random_shuffle( iterator start, iterator end );
      void random_shuffle( iterator start, iterator end, RandomNumberGenerator& rnd );
The random_shuffle() function randomly re-orders the elements in the range [start,end). If a random number generator function object rnd is supplied, it will be used instead of an internal random nunber generator. Related topics: next_permutation prev_permutation random_sample random_sample_n