Product of Array Except Self

For every position i, print the product of all the other numbers in the array (everything except a[i]).

Input:

• line 1: n
• line 2: n integers

Output: n numbers on one line — answer[i] = product of all a[k] with k ≠ i.

Constraints: 2 ≤ n ≤ 10⁵, −30 ≤ a[i] ≤ 30. Every product fits in a 64-bit integer (long / long long).

Rules: don't use division (zeros make it fail anyway). Aim for O(n): a product of everything to the left of i times everything to the right of i.