leetcode

0 class Solution {

1 public:

2 int numTilings(int n) const {

3 static const int MOD = 1E9 + 7;

4 static long long dp[1001] = {0, 1, 2, 5};

5 memset(dp + 4, 0x00, sizeof(dp) - 16);

6 if (n <= 3) return dp[n];

7 for (int i = 4; i <= n; i++) {

8 dp[i] = (2 * dp[i - 1] + dp[i - 3]) % MOD;

9 }

10 return dp[n];

11 }

12 };