human
Write me a code to mean of array generated by products of all pairs of the given array and the other steps required given the following:
Mean of array generated by products of all pairs of the given array | Function to find the mean of pair product array of arr [ ].
Initializing suffix sum array.
Build suffix sum array.
Size of pairProductArray.
Stores sum of pairProductArray.
Store the mean.
Find mean of pairProductArray.
Return the resultant mean.
Driver Code.
Given array arr [ ].
Function Call"
Solution in Python:
assistant
#Here is code to mean of array generated by products of all pairs of the given array and the other steps required.
 def pairProductMean ( arr , N ) :
	suffixSumArray = [ 0 ] * N
	suffixSumArray [ N - 1 ] = arr [ N - 1 ]
	for i in range ( N - 2 , - 1 , - 1 ) :
		suffixSumArray [ i ] = suffixSumArray [ i + 1 ] + arr [ i ]
	length = ( N * ( N - 1 ) ) // 2
	res = 0
	for i in range ( N - 1 ) :
		res += arr [ i ] * suffixSumArray [ i + 1 ]
	mean = 0
	if ( length != 0 ) :
		mean = res / length
	else :
		mean = 0
	return mean
if __name__ == ' _ _ main _ _ ' :
	arr = [ 1 , 2 , 4 , 8 ]
	N = len ( arr )
	print ( round ( pairProductMean ( arr , N ) , 2 ) )