Package g2301_2400.s2328_number_of_increasing_paths_in_a_grid

Class Solution

  • public class Solution
extends Object
    2328 - Number of Increasing Paths in a Grid.

    Hard

    You are given an m x n integer matrix grid, where you can move from a cell to any adjacent cell in all 4 directions.

    Return the number of strictly increasing paths in the grid such that you can start from any cell and end at any cell. Since the answer may be very large, return it modulo 109 + 7.

    Two paths are considered different if they do not have exactly the same sequence of visited cells.

    Example 1:

    Input: grid = [[1,1],[3,4]]

    Output: 8

    Explanation: The strictly increasing paths are:

    • Paths with length 1: [1], [1], [3], [4].

    • Paths with length 2: [1 -> 3], [1 -> 4], [3 -> 4].

    • Paths with length 3: [1 -> 3 -> 4].

    The total number of paths is 4 + 3 + 1 = 8.

    Example 2:

    Input: grid = [[1],[2]]

    Output: 3

    Explanation: The strictly increasing paths are:

    • Paths with length 1: [1], [2].

    • Paths with length 2: [1 -> 2].

    The total number of paths is 2 + 1 = 3.

    Constraints:

    • m == grid.length
    • n == grid[i].length
    • 1 <= m, n <= 1000
    • 1 <= m * n <= 105
    • 1 <= grid[i][j] <= 105

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • countPaths

        public int countPaths​(int[][] grid)