How can I use the mismatch() in CPP

[Garrett]

Hi, Everyone. I am studying in the first year of BSC- IT. I have the well knowledge of the C++ language. I can only know about the some of the built-in functions that can be defined in the C++ library. So, I want to know about the mismatch() function in C++ language. I also want to know about the use of the function mismatch() in the C++ programming. So, Can anyone help me to know about the mismatch() function.

[Zecho]

The mismatch() function can be used to find first position of an element where the two ranges can differ. The following can be the syntax of the mismatch() function as :

template <class IptItrtr1, class IptItrtr2>
  pair<IptItrtr1, IptItrtr2>
    mismatch (IptItrtr1 first1, IptItrtr1 last1,
              IptItrtr2 first2 );

[absolute55]

The following can be the program on the mismatch() function in the C++ language :

// mismatch algorithm example
#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
bool mypredicate (int p, int q)
 {
  return (p==q);
}
int main ()
 {
  vector<int> mvctr;
  for (int p=1; p<6; p++) mvctr.pushback (p*10); 
  int myint[] = {10,20,80,320,1024};                
  pair<vector<int>::iterator,int*> mypair;
  mypair = mismatch (mvctr.begin(), mvctr.end(), myint);
  cout << "First mismatching elements: " << *mypair.first;
  cout << " and " << *mypair.second << endl;;
  mypair.fst++; mypair.second++;
  mypair = mismatch (mypair.fst, mvctr.end(), mypair.second, mprdict);
  cout << "Second mismatching elements: " << *mypair.first;
  cout << " and " << *mypair.second << endl;;
   return 0;
}

Output of above :

First mismatching elements: 30 and 80
Second mismatching elements: 40 and 320

[Reegan]

The following can be the parameters of the mismatch() function in the C++ language :
1. fst2 : These parameters can be used in the C++ language for the forward iterator to the starting position of the sequence that can be second.
2. fst1, lst1 : These parameters can be used in the C++ language the forward iterators to the final and starting positions of the sequence that can be first.

[opaper]

Program :

      #include <algorithm>    
      #include <functional>   
      #include <iostream>     
      #include <utility>      
      #include <vector>     
      int main ()
      {
          typedef std::vector<int, std::allocator<int> > Vector;
          typedef Vector::const_iterator Itr;
          const Vector::valuetype c1[] = { 1, 2, 3, 4 };
          const Vector::valuetype c2[] = { 1, 3, 2, 4 };
          const Vector v1 (c1 + 0, c1 + sizeof c1 / sizeof *c1);
          const Vector v2 (c2 + 0, c2 + sizeof c2 / sizeof *c2);
          std::pair<Iter, Itr> q1 =
              std::mismatch (w1.begin (), w1.end (), w2.begin ());  
          std::pair<Iter, Itr> q2 =
              std::mismatch (w1.begin (), w1.end (),
                             w2.begin (), std::lessequal<int>());
          std::cout << *q1.first << ", " << *q1.second << std::endl;
          std::cout << *q2.first << ", " << *q2.second << std::endl;
          return 0;
      }

Output:

 2, 3
     3, 2

[MindSpace]

To compare an elements in the given range that can be defined by the [start1,end) to an elements that can be in a range of the same size that is starting at start2. The mismatch() function can returns the value either :
1. If the ranges can be an equal, end1 and the corresponding element in the range second.
2. The first location where the 2 ranges can be differ from each other.