function productExceptSelf(nums){
const n = nums.length;
const output = new Array(n).fill(1);
for(let i=1;i<n;i++){
output[i] = output[i-1]*nums[i-1]
}
let right =1;
for(let i =n-1;i>=0;i--){
output[i] *=right;
right*=nums[i]
}
return output
}
const nums = [1,2,3,4];
const result = productExceptSelf(nums);
console.log(result)