[20250223] BOJ / 골드4 / 타일 채우기 3 / 설진영

Author: Seol-JY

Seol-JY/202502/23 BOJ G4 타일 채우기 3.md

@@ -0,0 +1,24 @@
+```java
+import java.io.*;
+public class Main {
+	static int N;
+	static final int MOD = 1000000007;
+	static long[][] dp = new long[1000001][2];
+
+	public static void main(String[] args) throws IOException {
+		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+		N = Integer.parseInt(br.readLine());
+		dp[0][0] = 0;
+		dp[1][0] = 2;
+		dp[2][0] = 7;
+		dp[2][1] = 1;
+
+		for (int i = 3; i <= N; i++) {
+			dp[i][1] = (dp[i - 3][0] + dp[i - 1][1]) % MOD;  // i - 3 까지 누적합 + 1
+			dp[i][0] = (3 * (dp[i - 2][0]) + 2 * (dp[i - 1][0]) + 2 * dp[i][1]) % MOD;
+		}
+
+		System.out.println(dp[N][0]);
+	}
+}
+```