Write a C++ program to count a substring of length 2 appears in a given string and also as the last 2 characters of the string. Do not count the end substring

#include <iostream>
using namespace std;

int test(string str)
        {
            string last_two_char = str.substr(str.length()-2);
            int ctr = 0;

            for (int i = 0; i < str.length()-2; i++)
            {
               if (str.substr(i, 2) == (last_two_char)) ctr++;
            }
            return ctr;
        }
        
int main() 
 {
  cout << test("abcdsab") << endl;  
  cout << test("abcdabab") << endl;  
  cout << test("abcabdabab") << endl;  
  cout << test("abcabd") << endl;  
  return 0;    
}