Check if There is a Valid Path in a Grid LeetCode solution in Python

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class Solution:
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    def hasValidPath(self, grid: List[List[int]]) -> bool:
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        r, c = len(grid), len(grid[0])
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        dic = {
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            2: [(-1, 0), (1, 0)],
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            1: [(0, 1), (0, -1)],
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            5: [(-1, 0), (0, -1)],
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            3: [(1, 0), (0, -1)],
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            6: [(0, 1), (-1, 0)],
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            4: [(0, 1), (1, 0)],
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        }
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        q = collections.deque([(0, 0)])
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        visit = set()
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        while q:
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            i, j = q.popleft()
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            visit.add((i, j))
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            if i == r - 1 and j == c - 1:
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                return True
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            for x, y in dic[grid[i][j]]:
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                nx = i + x
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                ny = j + y
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                if nx >= 0 and nx < r and ny >= 0 and ny < c and (nx, ny) not in visit:
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                    if (-x, -y) in dic[grid[nx][ny]]:
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                        q.append((nx, ny))
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        return False