题目链接：https://pintia.cn/problem-sets/994805148990160896/problems/994805153880719360
参考博客：https://blog.csdn.net/u014646950/article/details/48683081
算法：dp
#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<string>
const int mod = 1e9 + 7;
#define maxn 510
using namespace std;
long long dp[maxn][maxn][2];
int n;
long long sum = 0;
void Dp() {
memset(dp, 0, sizeof(dp));
dp[0][0][1] = dp[1][0][0] = 1;
for (int i = 1; i < maxn; i++) {
for (int j = 1; j <= min(i,8); j++) {
for (int k = 0; k < i; k++) {
(dp[i][j][1] += (dp[k][j - 1][1] + dp[k][j - 1][0])*(dp[i - k - 1][j - 1][1] + dp[i - k - 1][j - 1][0]) % mod) %= mod;
(dp[i][j][0] += dp[k][j][1] * dp[i - k - 1][j][1] % mod)%=mod;
}
if (i == n) {
sum += dp[i][j][1];
sum%=mod;
}
}
}
}
int main() {
cin >> n;
Dp();
cout << sum << endl;
return 0;
}