The importance of counting HH&LL is to find the possible extreme of the current leg and the potential reversal.
This script helps you count the number of bars which are constantly higher or lower than the previous ones. I set the script to count from the first one, but only display the number from the third, in order to eliminate too much noise.
Note: I have loosened the criteria of HH and LL. Let's take "higher high" as an example, I will count the number If the current bar's low is higher than the previous one's and its high is higher or equal to the previous one's , and vice versa.
If you prefer the strict definition of HH or LL, you can modify the code as you wish.