238. Product of Array Except Self

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

Example:

```Input:  `[1,2,3,4]`
Output: `[24,12,8,6]`
```

Constraint: It's guaranteed that the product of the elements of any prefix or suffix of the array (including the whole array) fits in a 32 bit integer.

Note: Please solve it without division and in O(n).

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

238. Product of Array Except Self
``````struct Solution;

impl Solution {
fn product_except_self(nums: Vec<i32>) -> Vec<i32> {
let n = nums.len();
let mut res: Vec<i32> = vec![1; n];
let mut product = 1;
for i in 0..n {
res[i] *= product;
product *= nums[i];
}
product = 1;
for i in (0..n).rev() {
res[i] *= product;
product *= nums[i];
}
res
}
}

#[test]
fn test() {
let nums = vec![1, 2, 3, 4];
let res = vec![24, 12, 8, 6];
assert_eq!(Solution::product_except_self(nums), res);
}
``````