/**
 * 
 * Ashish Patel
 * e: ashishsushilPatel@gmail.com
 * w: https://ashish.me
 *
 */

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

function productOfArrayExceptSelf(nums) {
  let res = [1], back = 1
  for (let index = 1; index < nums.length; index++) {
      res[index] = res[index-1] * nums[index-1]
  }
  for (let index = nums.length - 2 ; index >= 0 ; index--) {
    back = back * nums[index + 1]
    res[index] = res[index] * back  
  }
  return res
}

console.log(productOfArrayExceptSelf([1,2,3,4]))

// test('product Of Array Except Self', () => {
//   expect(productOfArrayExceptSelf([1,2,3,4])).toEqual([24,12,8,6])
// });