cppreference.com > C++ Algorithms > lexicographical_compare_3way lexicographical_compare_3way Syntax:
      #include <algorithm>
      int lexicographical_compare_3way( iterator start1, iterator end1, iterator start2, iterator end2 );
The lexicographical_compare_3way() function compares the first range, defined by [start1,end1) to the second range, defined by [start2,end2). If the first range is lexicographically less than the second range, this function returns a negative number. If the first range is lexicographically greater than the second, a positive number is returned. Zero is returned if neither range is lexicographically greater than the other. lexicographical_compare_3way() runs in linear time. Related topics: lexicographical_compare