You have a grid of size n x 3 and you want to paint each cell of the grid with exactly one of the three colors: Red, Yellow, or Green while making sure that no two adjacent cells have the same color (i.e., no two cells that share vertical or horizontal sides have the same color).
Given n the number of rows of the grid, return the number of ways you can paint this grid. As the answer may grow large, the answer must be computed modulo 109 + 7.
Example 1:
Input: n = 1 Output: 12 Explanation: There are 12 possible way to paint the grid as shown.
Example 2:
Input: n = 2 Output: 54
Example 3:
Input: n = 3 Output: 246
Example 4:
Input: n = 7 Output: 106494
Example 5:
Input: n = 5000 Output: 30228214
Constraints:
n == grid.lengthgrid[i].length == 31 <= n <= 5000