human
What is a code to count pairs of indices having equal prefix and suffix sums and the other steps required given the following:
Count pairs of indices having equal prefix and suffix sums | Function to find the count of index pairs having equal prefix and suffix sums.
Maps indices with prefix sums.
Traverse the array.
Update prefix sum.
Update frequency in Map.
Traverse the array in reverse.
Update suffix sum.
Check if any prefix sum of equal value exists or not.
Print the obtained count.
Driver code.
Given array.
Given size.
Function Call"
How can the above be solved in Python?
assistant
#Here is code to count pairs of indices having equal prefix and suffix sums and the other steps required.
 def countPairs ( arr , n ) :
	mp1 = { }
	sum = 0
	for i in range ( n ) :
		sum += arr [ i ]
		mp1 [ sum ] = mp1 . get ( sum , 0 ) + 1
	sum = 0
	ans = 0
	for i in range ( n - 1 , - 1 , - 1 ) :
		sum += arr [ i ]
		if ( sum in mp1 ) :
			ans += mp1 [ sum ]
	print ( ans )
if __name__ == ' _ _ main _ _ ' :
	arr = [ 1 , 2 , 1 , 1 ]
	n = len ( arr )
	countPairs ( arr , n )