1391. Check if There is a Valid Path in a Grid

https://leetcode.com/problems/check-if-there-is-a-valid-path-in-a-grid

Description

Given a m x n grid. Each cell of the grid represents a street. The street of grid[i][j] can be:

• 1 which means a street connecting the left cell and the right cell.

• 2 which means a street connecting the upper cell and the lower cell.

• 3 which means a street connecting the left cell and the lower cell.

• 4 which means a street connecting the right cell and the lower cell.

• 5 which means a street connecting the left cell and the upper cell.

• 6 which means a street connecting the right cell and the upper cell.

You will initially start at the street of the upper-left cell (0,0). A valid path in the grid is a path which starts from the upper left cell (0,0) and ends at the bottom-right cell (m - 1, n - 1). The path should only follow the streets.

Notice that you are not allowed to change any street.

Return true if there is a valid path in the grid or false otherwise.

Example 1:

**Input:** grid = [[2,4,3],[6,5,2]]
**Output:** true
**Explanation:** As shown you can start at cell (0, 0) and visit all the cells of the grid to reach (m - 1, n - 1).

Example 2:

**Input:** grid = [[1,2,1],[1,2,1]]
**Output:** false
**Explanation:** As shown you the street at cell (0, 0) is not connected with any street of any other cell and you will get stuck at cell (0, 0)

Example 3:

**Input:** grid = [[1,1,2]]
**Output:** false
**Explanation:** You will get stuck at cell (0, 1) and you cannot reach cell (0, 2).

Example 4:

**Input:** grid = [[1,1,1,1,1,1,3]]
**Output:** true

Example 5:

**Input:** grid = [[2],[2],[2],[2],[2],[2],[6]]
**Output:** true

Constraints:

• m == grid.length

• n == grid[i].length

• 1 <= m, n <= 300

• 1 <= grid[i][j] <= 6

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