Product of Array Except Self

Description:

Given an array of n integers where n > 1, nums, return an array output such that output[i] is equal to the product of all the elements of nums except nums[i].

Solve it without division and in O(n).

For example, given [1,2,3,4], return [24,12,8,6].

Follow up:

Could you solve it with constant space complexity? (Note: The output array does not count as extra space for the purpose of space complexity analysis.)

Solution:

class Solution {
public:
vector productExceptSelf(vector& nums) {
auto sz = (int)nums.size();
vector rc(sz, 1);
int first = 1;
int last = 1;
for (int i = 0; i < sz; ++i) {
rc[i] *= first;
first *= nums[i];
rc[sz-i-1] *= last;
last *= nums[sz-i-1];
}
return rc;
}
};