题解 | 牛牛学数列6
牛牛学数列6
https://www.nowcoder.com/practice/b6321648517247b2ac2e2f80cbc63ae1
#include<bits/stdc++.h>
using namespace std;
int a[100];
int main(){
int n;
cin>>n;
a[1]=0,a[2]=1,a[3]=1;
for(int i=4;i<=n;i++){
a[i]=a[i-1]+2*a[i-2]+a[i-3];
}
cout<<a[n];
return 0;
}
