ReverseDistance | Topcoder Archive

Problem Statement

To obtain the reverse of a number, write it backwards from right to left. For example, the reverse of 1234 is 4321, and the reverse of 100 is 1 (leading zeroes are always ignored). Return the smallest non-negative number x, such that the difference x - reverse(x) is equal to difference. If no such number exists, return "NONE" (quotes for clarity) instead.

Definition

Class:: ReverseDistance
Method:: find
Parameters:: int
Returns:: String
Method signature:: String find(int difference)
(be sure your method is public)

Constraints

difference will be between 1 and 1000000, inclusive.

Examples

```
18
```
```
Returns: "20"
```
20 - 2 = 18. 18 can be also achieved in other ways like 42 - 24, but 20 is the smallest possible number.
```
15
```
```
Returns: "NONE"
```
It's impossible to find a number with a difference of 15.
```
4275
```
```
Returns: "5080"
```
5080 - 805 = 4275
```
900
```
```
Returns: "101001"
```
101001 - 100101 = 900
```
1989
```
```
Returns: "100990"
```
100990 - 99001 = 1989
```
857232
```
```
Returns: "860300"
```
860300 - 3068 = 857232
```
45
```
```
Returns: "50"
```

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