238. 除自身以外数组的乘积

[1,2,3,4]

class Solution:
    def productExceptSelf(self, nums: List[int]) -> List[int]:
        n = len(nums)
        output = [1 for _ in nums]
        left = right = 1
        for i in range(n):
            output[i] = left
            left *= nums[i]
        for i in range(n - 1, -1, -1):
            output[i] *= right
            right *= nums[i]
        return output

class Solution {
    public int[] productExceptSelf(int[] nums) {
        int n = nums.length;
        int[] output = new int[n];
        for (int i = 0, left = 1; i < n; ++i) {
            output[i] = left;
            left *= nums[i];
        }
        for (int i = n - 1, right = 1; i >= 0; --i) {
            output[i] *= right;
            right *= nums[i];
        }
        return output;
    }
}

/**
 * @param {number[]} nums
 * @return {number[]}
 */
var productExceptSelf = function (nums) {
  const n = nums.length;
  let output = new Array(n);
  for (let i = 0, left = 1; i < n; ++i) {
    output[i] = left;
    left *= nums[i];
  }
  for (let i = n - 1, right = 1; i >= 0; --i) {
    output[i] *= right;
    right *= nums[i];
  }
  return output;
};