Problem

You are given a 2D matrix grid of size m x n. You need to check if each cell grid[i][j] is:

Equal to the cell below it, i.e. grid[i][j] == grid[i + 1][j] (if it exists).
Different from the cell to its right, i.e. grid[i][j] != grid[i][j + 1] (if it exists).

Return true if all the cells satisfy these conditions, otherwise, return false.

Example 1:

Input: grid = [[1,0,2],[1,0,2]]

Output: true

Explanation:

All the cells in the grid satisfy the conditions.

Example 2:

Input: grid = [[1,1,1],[0,0,0]]

Output: false

Explanation:

All cells in the first row are equal.

Example 3:

Input: grid = [[1],[2],[3]]

Output: false

Explanation:

Cells in the first column have different values.

Constraints: