Distinct Islands Counting

You are given a grid representing a map where each cell is either land or water. Land is denoted by the character L and water by W. Two land cells are considered connected if they are adjacent horizontally or vertically (diagonals do not count).

The first line of the input contains two integers n and m which represent the number of rows and columns of the grid respectively. This is followed by n lines, each containing a string of length m (without spaces) that represents a row in the grid.

The goal is to count the number of distinct islands in the grid.

An island is a group of one or more L cells connected together horizontally or vertically. In mathematical terms, if we denote the position of a cell by \((i,j)\), then two cells \((i_1, j_1)\) and \((i_2, j_2)\) are adjacent if and only if \[ |i_1 - i_2| + |j_1 - j_2| = 1. \]

inputFormat

The first line contains two space‐separated integers n and m (the number of rows and columns respectively).

The next n lines each contain a string of length m composed only of the characters L and W.

outputFormat

Output a single integer denoting the number of distinct islands in the grid.

4 5
LLWLL
LWWLW
WWWLL
LLLWL

3