Islands | Topcoder Archive

Problem Statement

The king is trying to find new ways to generate revenue, and he is currently exploring tourism as one potential avenue. The kingdom is a group of islands, and the amount of revenue that can be generated depends on the combined total length of beaches on all the islands.

You are given a String[] kingdom consisting of '.' or '#' characters. '#' represents a land mass, whereas '.' represents water. kingdom[i][j] represents a regular-hexagon shaped area with each side of unit length. Since the cells are hexagonal in shape, the odd-numbered rows (0-based) are 'shifted' towards the right. A beach is a segment which has water on one side, and land on the other.
An example String[] and the corresponding image are given below to illustrate. The beaches are marked in red.

{"..#.##",
 ".##.#.",
 "#.#..."}

Return the combined total length of beaches on all the islands.

Definition

Class:: Islands
Method:: beachLength
Parameters:: String[]
Returns:: int
Method signature:: int beachLength(String[] kingdom)
(be sure your method is public)

Constraints

kingdom will contain between 1 and 50 elements, inclusive.
Each element of kingdom will contain between 1 and 50 characters, inclusive.
Each element of kingdom will contain the same number of characters.
Each character in kingdom will be either '.' or '#'.

Examples

```
{".#...#.."}
```
```
Returns: 4
```
There are two small islands with water on two sides of each island.

{"..#.##", 
 ".##.#.", 
 "#.#..."}

Returns: 19

The example in the problem statement.

{"#...#.....",
 "##..#...#."}

Returns: 15

{"....#.",
 ".#....",
 "..#..#",
 "####.."}

Returns: 24

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