DigitalCounter | Topcoder Archive

Problem Statement

We have an N-digit digital counter that increments every second. The counter is cyclic: after it reaches 10^N - 1, it starts once again from zero.

Each digit is shown using the standard seven-segment display. The exact forms of all the digits are shown in the ASCII art below.

    +   +---+   +---+   +   +   +---+
    |       |       |   |   |   |
    +   +---+   +---+   +---+   +---+
    |   |           |       |       |
    +   +---+   +---+       +   +---+

+---+   +---+   +---+   +---+   +---+
|           |   |   |   |   |   |   |
+---+       +   +---+   +---+   +   +
|   |       |   |   |       |   |   |
+---+       +   +---+       +   +---+

Each line segment that connects two adjacent '+' symbols represents a single lit segment. For example, '1' contains two lit segments, and '9' contains five lit segments.

You are given a String current that contains the current number shown by the counter.
The number of characters in current is equal to the number N of displayed digits.

Return the smallest positive number of seconds after which the counter will have the same total number of lit segments as it does now.

Definition

Class:: DigitalCounter
Method:: nextEvent
Parameters:: String
Returns:: long
Method signature:: long nextEvent(String current)
(be sure your method is public)

Notes

The digits 1, 2, ..., 9, and 0 have 2, 5, 5, 4, 5, 6, 3, 7, 5, and 6 lit segments, respectively.
The counter does always show leading zeroes. (See Examples #3 and #5.)
As the counter is cyclic, the answer always exists and for any valid input the answer fits into a long.

Constraints

current will contain between 1 and 15 characters, inclusive.
Each character in current will be a digit ('0'-'9').

Examples

```
"1"
```
```
Returns: 10
```
No other digit has exactly two segments lit, thus the next time there will be two segments lit will be in 10 seconds.
```
"3"
```
```
Returns: 2
```
In 2 seconds the display will show "5", and "5" and "3" both have exactly five lit segments.
```
"9"
```
```
Returns: 3
```
In 3 seconds, the display will show "2".
```
"99"
```
```
Returns: 5
```
The number "99" is shown using 5+5=10 lit segments. In 5 seconds, the display will show "04", with 6+4=10 lit segments again.
```
"654371"
```
```
Returns: 43
```
```
"007"
```
```
Returns: 11
```
Note that the input can have leading zeroes.

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