cppreference.com > C++ Algorithms > mismatch mismatch Syntax:
      #include <algorithm>
      pair <iterator1,iterator2> mismatch( iterator start1, iterator end1, iterator start2 );
      pair <iterator1,iterator2> mismatch( iterator start1, iterator end1, iterator start2, BinPred p );
The mismatch() function compares the elements in the range defined by [start1,end1) to the elements in a range of the same size starting at start2. The return value of mismatch() is the first location where the two ranges differ. If the optional binary predicate p is given, then it is used to compare elements from the two ranges. The mismatch() algorithm runs in linear time. Related topics: equal find lexicographical_compare search