文章目录
暴力法（26分）
#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
const int N = 1010 ,mod = 998244353;
int n;
string S;
string s[N];
int main()
{
cin >> n >> S;
s[1] = "2",s[2] = "4",s[3] = "16", s[4] = "264", s[5] = "46416";
for(int i=5; i <= n ; i ++)
{
s[i] = s[i-3] + s[i-1].substr(s[i-4].size()) + s[i-2];
}
int p = s[n].find(S);
int cnt = 0;
while(p != -1)
{
cnt = (cnt + 1) % mod;
p++;
p = s[n].find(S,p);
}
cout<<cnt<<endl;
return 0;
}