1411. Number of Ways to Paint N × 3 Grid

/**
 * Problem: LeetCode 1411 - Number of Ways to Paint N × 3 Grid
 * Difficulty: Hard
 * Language: Java
 * Author: CodeByTushu
 */
class Solution {
    public int numOfWays(int n) {
        long color2 = 6; // Patterns with 2 distinct colors (e.g., ABA)
        long color3 = 6; // Patterns with 3 distinct colors (e.g., ABC)
        long mod = 1_000_000_007L;

        for (int i = 2; i <= n; i++) {
            long nextColor2 = (3 * color2 + 2 * color3) % mod;
            long nextColor3 = (2 * color2 + 2 * color3) % mod;
            color2 = nextColor2;
            color3 = nextColor3;
        }

        return (int) ((color2 + color3) % mod);
    }
}

"""
Problem: LeetCode 1411 - Number of Ways to Paint N × 3 Grid
Difficulty: Hard
Language: Python
Author: CodeByTushu
"""
class Solution:
    def numOfWays(self, n: int) -> int:
        MOD = 1_000_000_007
        color2 = 6  # Patterns with 2 distinct colors (e.g., ABA)
        color3 = 6  # Patterns with 3 distinct colors (e.g., ABC)

        for _ in range(2, n + 1):
            next_color2 = (3 * color2 + 2 * color3) % MOD
            next_color3 = (2 * color2 + 2 * color3) % MOD
            color2, color3 = next_color2, next_color3

        return (color2 + color3) % MOD

/**
 * Problem: LeetCode 1411 - Number of Ways to Paint N × 3 Grid
 * Difficulty: Hard
 * Language: C++
 * Author: CodeByTushu
 */
class Solution {
public:
    int numOfWays(int n) {
        long long color2 = 6; // Patterns with 2 distinct colors (e.g., ABA)
        long long color3 = 6; // Patterns with 3 distinct colors (e.g., ABC)
        const int MOD = 1e9 + 7;

        for (int i = 2; i <= n; i++) {
            long long nextColor2 = (3 * color2 + 2 * color3) % MOD;
            long long nextColor3 = (2 * color2 + 2 * color3) % MOD;
            color2 = nextColor2;
            color3 = nextColor3;
        }

        return (color2 + color3) % MOD;
    }
};

/**
 * Problem: LeetCode 1411 - Number of Ways to Paint N × 3 Grid
 * Difficulty: Hard
 * Language: JavaScript
 * Author: CodeByTushu
 */
/**
 * @param {number} n
 * @return {number}
 */
var numOfWays = function(n) {
    const MOD = 1000000007n;
    let color2 = 6n; // Patterns with 2 distinct colors (e.g., ABA)
    let color3 = 6n; // Patterns with 3 distinct colors (e.g., ABC)

    for (let i = 2; i <= n; i++) {
        const nextColor2 = (3n * color2 + 2n * color3) % MOD;
        const nextColor3 = (2n * color2 + 2n * color3) % MOD;
        color2 = nextColor2;
        color3 = nextColor3;
    }

    return Number((color2 + color3) % MOD);
};