1411. Number of Ways to Paint N × 3 Grid

https://leetcode.com/problems/number-of-ways-to-paint-n-3-grid

Description

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.length

• grid[i].length == 3

• 1 <= n <= 5000

ac