动态规划

using namespace std;
int n;
int dp[1005][1005][2];
int num[1005];
const int p = 19650827;
int ()
{
    cin >> n;
    for (int i = 1; i <= n;i++)
    {
        cin >> num[i];
    }
    for (int i = 1; i <= n;i++)
    {
        dp[i][i][0] = 1;
    }
    for (int l = 1; l <= n; l++)
    {
        for (int i = 1, j; (j=i+l) <= n; i++)
        {
            dp[i][j][0] = (dp[i + 1][j][1] * (num[j] > num[i]) + dp[i + 1][j][0] * (num[i + 1] > num[i])) % p;
            dp[i][j][1] = (dp[i][j - 1][1] * (num[j] > num[j - 1]) + dp[i][j-1][0] * (num[j] > num[i])) % p;
        }
    }
    cout << (dp[1][n][0] + dp[1][n][1]) % p << endl;
}