Package g1301_1400.s1391_check_if_there_is_a_valid_path_in_a_grid

Class Solution

  • public class Solution
extends Object
    1391 - Check if There is a Valid Path in a Grid.

    Medium

    You are given an m x n grid. Each cell of 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 that 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).

    Constraints:

    • m == grid.length
    • n == grid[i].length
    • 1 <= m, n <= 300
    • 1 <= grid[i][j] <= 6

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • hasValidPath

        public boolean hasValidPath​(int[][] grid)