human
Count number of common elements between a sorted array and a reverse sorted array | Function to count the number of elements common in both the arrays.
Used to traverse array A [ ] and B [ ] from the front and the back.
Stores the count of numbers common in both array.
If A [ first ] is less than B [ second ].
Increment the value of first.
IF B [ second ] is less than A [ first ].
Decrement the value of second.
A [ first ] is equal to B [ second ].
Increment the value of count.
Increment the value of first.
Decrement the value of second.
Return the value of count.
Driver Code"
How can the above be solved in Python?
 Can you provide a code to count number of common elements between a sorted array and a reverse sorted array and the other steps required?
assistant
#Here is code to count number of common elements between a sorted array and a reverse sorted array and the other steps required.
 def countEqual ( A , B , N ) :
	first = 0
	second = N - 1
	count = 0
	while ( first < N and second >= 0 ) :
		if ( A [ first ] < B [ second ] ) :
			first += 1
		elif ( B [ second ] < A [ first ] ) :
			second -= 1
		else :
			count += 1
			first += 1
			second -= 1
	return count
A = [ 2 , 4 , 5 , 8 , 12 , 13 , 17 , 18 , 20 , 22 , 309 , 999 ]
B = [ 109 , 99 , 68 , 54 , 22 , 19 , 17 , 13 , 11 , 5 , 3 , 1 ]
N = len ( A )
print ( countEqual ( A , B , N ) )