2684. Maximum Number of Moves in a Grid LeetCode Solution

In this guide, you will get 2684. Maximum Number of Moves in a Grid LeetCode Solution with the best time and space complexity. The solution to Maximum Number of Moves in a Grid problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.

Table of Contents

  1. Problem Statement
  2. Complexity Analysis
  3. Maximum Number of Moves in a Grid solution in C++
  4. Maximum Number of Moves in a Grid solution in Java
  5. Maximum Number of Moves in a Grid solution in Python
  6. Additional Resources
2684. Maximum Number of Moves in a Grid LeetCode Solution image

Problem Statement of Maximum Number of Moves in a Grid

You are given a 0-indexed m x n matrix grid consisting of positive integers.
You can start at any cell in the first column of the matrix, and traverse the grid in the following way:

From a cell (row, col), you can move to any of the cells: (row – 1, col + 1), (row, col + 1) and (row + 1, col + 1) such that the value of the cell you move to, should be strictly bigger than the value of the current cell.

Return the maximum number of moves that you can perform.

Example 1:

Input: grid = [[2,4,3,5],[5,4,9,3],[3,4,2,11],[10,9,13,15]]
Output: 3
Explanation: We can start at the cell (0, 0) and make the following moves:
– (0, 0) -> (0, 1).
– (0, 1) -> (1, 2).
– (1, 2) -> (2, 3).
It can be shown that it is the maximum number of moves that can be made.
Example 2:

See also  2409. Count Days Spent Together LeetCode Solution

Input: grid = [[3,2,4],[2,1,9],[1,1,7]]
Output: 0
Explanation: Starting from any cell in the first column we cannot perform any moves.

Constraints:

m == grid.length
n == grid[i].length
2 <= m, n <= 1000
4 <= m * n <= 105
1 <= grid[i][j] <= 106

Complexity Analysis

  • Time Complexity: O(mn)
  • Space Complexity: O(mn)

2684. Maximum Number of Moves in a Grid LeetCode Solution in C++

class Solution {
 public:
  int maxMoves(vector<vector<int>>& grid) {
    const int m = grid.size();
    const int n = grid[0].size();
    int ans = 0;
    // dp[i][j] := the maximum number of moves you can perform from (i, j)
    vector<vector<int>> dp(m, vector<int>(n));

    for (int j = n - 2; j >= 0; --j)
      for (int i = 0; i < m; ++i) {
        if (grid[i][j + 1] > grid[i][j])
          dp[i][j] = 1 + dp[i][j + 1];
        if (i > 0 && grid[i - 1][j + 1] > grid[i][j])
          dp[i][j] = max(dp[i][j], 1 + dp[i - 1][j + 1]);
        if (i + 1 < m && grid[i + 1][j + 1] > grid[i][j])
          dp[i][j] = max(dp[i][j], 1 + dp[i + 1][j + 1]);
      }

    for (int i = 0; i < m; ++i)
      ans = max(ans, dp[i][0]);

    return ans;
  }
};
/* code provided by PROGIEZ */

2684. Maximum Number of Moves in a Grid LeetCode Solution in Java

class Solution {
  public int maxMoves(int[][] grid) {
    final int m = grid.length;
    final int n = grid[0].length;
    int ans = 0;
    // dp[i][j] := the maximum number of moves you can perform from (i, j)
    int[][] dp = new int[m][n];

    for (int j = n - 2; j >= 0; --j)
      for (int i = 0; i < m; ++i) {
        if (grid[i][j + 1] > grid[i][j])
          dp[i][j] = 1 + dp[i][j + 1];
        if (i > 0 && grid[i - 1][j + 1] > grid[i][j])
          dp[i][j] = Math.max(dp[i][j], 1 + dp[i - 1][j + 1]);
        if (i + 1 < m && grid[i + 1][j + 1] > grid[i][j])
          dp[i][j] = Math.max(dp[i][j], 1 + dp[i + 1][j + 1]);
      }

    for (int i = 0; i < m; ++i)
      ans = Math.max(ans, dp[i][0]);

    return ans;
  }
}
// code provided by PROGIEZ

2684. Maximum Number of Moves in a Grid LeetCode Solution in Python

class Solution:
  def maxMoves(self, grid: list[list[int]]) -> int:
    m = len(grid)
    n = len(grid[0])
    # dp[i][j] := the maximum number of moves you can perform from (i, j)
    dp = [[0] * n for _ in range(m)]

    for j in range(n - 2, -1, -1):
      for i in range(m):
        if grid[i][j + 1] > grid[i][j]:
          dp[i][j] = 1 + dp[i][j + 1]
        if i > 0 and grid[i - 1][j + 1] > grid[i][j]:
          dp[i][j] = max(dp[i][j], 1 + dp[i - 1][j + 1])
        if i + 1 < m and grid[i + 1][j + 1] > grid[i][j]:
          dp[i][j] = max(dp[i][j], 1 + dp[i + 1][j + 1])

    return max(dp[i][0] for i in range(m))
# code by PROGIEZ

Additional Resources

See also  2673. Make Costs of Paths Equal in a Binary Tree LeetCode Solution

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