In a N x N grid composed of 1 x 1 squares, each 1 x 1 square consists of a /, \, or blank space.  These characters divide the square into contiguous regions.
(Note that backslash characters are escaped, so a \ is represented as "\\".)
Return the number of regions.
 













Example 1:
Input:
[
  " /",
  "/ "
]
Output: 2
Explanation: The 2x2 grid is as follows:



Example 2:
Input:
[
  " /",
  "  "
]
Output: 1
Explanation: The 2x2 grid is as follows:



Example 3:
Input:
[
  "\\/",
  "/\\"
]
Output: 4
Explanation: (Recall that because \ characters are escaped, "\\/" refers to \/, and "/\\" refers to /\.)
The 2x2 grid is as follows:



Example 4:
Input:
[
  "/\\",
  "\\/"
]
Output: 5
Explanation: (Recall that because \ characters are escaped, "/\\" refers to /\, and "\\/" refers to \/.)
The 2x2 grid is as follows:



Example 5:
Input:
[
  "//",
  "/ "
]
Output: 3
Explanation: The 2x2 grid is as follows:


 
Note:

1 <= grid.length == grid[0].length <= 30
grid[i][j] is either '/', '\', or ' '.

```python

USER_FILENAME = "<user_code>"
import sys, json, builtins
import math, heapq, bisect, itertools, functools, collections, statistics, fractions, decimal, operator, array, random, re, string, os, pathlib
try:
    import resource as _res
except Exception:
    _res = None
from collections import Counter, defaultdict, deque, OrderedDict
from functools import lru_cache, reduce
from itertools import accumulate, permutations, combinations, product
from math import gcd, ceil, floor, sqrt
from decimal import Decimal
try:
    from typing import *
except Exception:
    pass
try:
    sys.setrecursionlimit(1_000_000)
except Exception:
    pass
try:
    import site as _site
    try:
        _sys_sites = _site.getsitepackages() if hasattr(_site, "getsitepackages") else []
        for _p in _sys_sites:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
    try:
        _usp = _site.getusersitepackages()
        if isinstance(_usp, str):
            _usp = [_usp]
        for _p in _usp:
            if _p and _p not in sys.path:
                sys.path.append(_p)
    except Exception:
        pass
except Exception:
    pass

def _disabled_input(*args, **kwargs):
    raise RuntimeError("input() is disabled in callable mode")
builtins.input = _disabled_input

ns = {"__name__": "__judge__"}  # prevent if __name__ == "__main__" blocks
for _k, _v in list(globals().items()):
    if not _k.startswith("_"):
        ns[_k] = _v
_CODE = "class Solution:\n    def regionsBySlashes(self, grid: List[str]) -> int:\n        self.N = len(grid)#n行\n        print((self.N))\n        pre = list(range(self.N*self.N*4))#所有元素自己是自己的父节点[0,1,2,3,4,5,6,...]\n        self.count = self.N*self.N*4 #总共的区域数量\n        for r in range(self.N):\n            line = grid[r]\n            for c in range(self.N):\n                w = line[c]\n                if r > 0:\n                    self.union(pre, self.g(r - 1, c, 2), self.g(r, c, 0))\n                if c > 0:\n                    self.union(pre, self.g(r, c - 1, 1), self.g(r, c, 3))\n                if w != '/':\n                    self.union(pre, self.g(r, c, 0), self.g(r, c, 1))\n                    self.union(pre, self.g(r, c, 3), self.g(r, c, 2))\n                if w != '\\\\\\\\':\n                    self.union(pre, self.g(r, c, 0), self.g(r, c, 3))\n                    self.union(pre, self.g(r, c, 1), self.g(r, c, 2))\n        return self.count   \n        \n    def find(self,pre,x):\n        if x == pre[x]:\n            return x\n            \n        return self.find(pre,pre[x])\n    def union(self, pre, a, b):\n        pa = self.find(pre, a)\n        pb = self.find(pre, b)\n        if (pa == pb):\n            return\n        pre[pa] = pb\n        self.count -= 1\n    \n    def g(self, r, c, i):\n        return (r * self.N + c) * 4 + i\n"
_co = compile(_CODE, USER_FILENAME, "exec")
exec(_co, ns, ns)

_target = None
_fn_name = 'regionsBySlashes'
if _fn_name:
    if "Solution" in ns:
        try:
            _obj = ns["Solution"]()
            if hasattr(_obj, _fn_name):
                _target = getattr(_obj, _fn_name)
        except Exception:
            _target = None
    if _target is None and _fn_name in ns and callable(ns[_fn_name]):
        _target = ns[_fn_name]
# Fallback: if there's exactly one user-defined function, use it
if _target is None:
    _cands = [v for k, v in ns.items() if callable(v) and getattr(v, "__module__", "") in ("__judge__", "__main__")]
    _user_funcs = [c for c in _cands if getattr(c, "__name__", "").startswith("_") is False]
    if len(_user_funcs) == 1:
        _target = _user_funcs[0]
if _target is None:
    raise RuntimeError(f"Could not resolve callable '{_fn_name}'")

_raw = sys.stdin.read().strip()
if _raw:
    _parsed = json.loads(_raw)
    if isinstance(_parsed, dict):
        _kwargs = _parsed.get("kwargs", {})
        _args = _parsed.get("args", [])
    else:
        _args, _kwargs = _parsed, {}
else:
    _args, _kwargs = [], {}
if not isinstance(_args, (list, tuple)):
    _args = [_args]
_res = _target(*_args, **_kwargs)
try:
    sys.stdout.write(repr(_res) + "\n")
except Exception:
    pass

```

Measured memory_bytes: 7694