To find the product of every element other than itself without using division operator in O (n) time.

 For Example: Consider the below array 

1	2	3	4
A[0]	A[1]	A[2]	A[3]

To get the product of every element other than itself without using division operator in O (n) time, we use

Product of all array elements except the current element =

Product of all elements below the current index * Product of all elements above the current index

 

So Product of all elements below the current index is

1	1	2	6
A[0]	A[1]	A[2]	A[3]

 

Product of all elements above the current index is

24	12	4	1
A[0]	A[1]	A[2]	A[3]

 

Product of both would be

24	12	8	6
A[0]	A[1]	A[2]	A[3]