0959. Regions Cut By Slashes

https://leetcode.com/problems/regions-cut-by-slashes

Description

An n x n grid is composed of 1 x 1 squares where each 1 x 1 square consists of a '/', '\', or blank space ' '. These characters divide the square into contiguous regions.

Given the grid grid represented as a string array, return the number of regions.

Note that backslash characters are escaped, so a '\' is represented as '\\'.

Example 1:

**Input:** grid = [" /","/ "]
**Output:** 2

Example 2:

**Input:** grid = [" /","  "]
**Output:** 1

Example 3:

**Input:** grid = ["\\/","/\\"]
**Output:** 4
**Explanation:** (Recall that because \ characters are escaped, "\\/" refers to \/, and "/\\" refers to /\.)

Example 4:

**Input:** grid = ["/\\","\\/"]
**Output:** 5
**Explanation:** (Recall that because \ characters are escaped, "\\/" refers to \/, and "/\\" refers to /\.)

Example 5:

**Input:** grid = ["//","/ "]
**Output:** 3

Constraints:

• n == grid.length

• n == grid[i].length

• 1 <= n <= 30

• grid[i][j] is either '/', '\', or ' '.

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