Sum of two arrays : I am unable to figure out the problem

1.Traverse both the arrays simultaneously from the end until we reach the 0th index of either of the array.
2.While traversing each element of array, add an element from both arrays and carry from the previous sum.
…………2.1 Store the unit digit of the sum(obtained by doing - sum%10) in the ans array.
…………2.2 forward carry(obtained by doing - sum/10) for the next index sum.
3.After the loop ends we are left with one of the arrays and the carry.
4.We will now repeat step 2 but now for one array which is left after the loop.
5.If carry !=0 then store the carry in the 0th index of ans array.
6.Print the ans array .