Add 1 to an integer in the form of array using Java
How can you convert a number which is available in the form of array to a new array by adding 1 to it. How would you do it in Java without using any extra storage & with best time complexity of O(n)?

Example: 
Input number is also in the form of array.
  
     748 [7,4,8] would be 749 as [7,4,9]
     999 [9,9,9] would be 1000 as [1,0,0,0]

I tried from reverse end & started adding 1 but the interviewer was not happy with this answer. So I was wondering if there is a better approach & if someone can provide java code snippet?
Add 1 to an integer in the form of array using Java
===

How can you convert a number which is available in the form of array to a new array by adding 1 to it. How would you do it in Java without using any extra storage & with best time complexity of O(n)?

Example: 
Input number is also in the form of array.
  
     748 [7,4,8] would be 749 as [7,4,9]
     999 [9,9,9] would be 1000 as [1,0,0,0]

I tried from reverse end & started adding 1 but the interviewer was not happy with this answer. So I was wondering if there is a better approach & if someone can provide java code snippet?