可以用dp，效率更高。
by xiaoshumiao @ 2023-10-19 18:16:51
@[xiaoshumiao](/user/1008513) Thanks♪(･ω･)ﾉ，用了dp就过了
by Flechazo_07 @ 2023-10-19 22:29:45
代码：
```c
#include<bits/stdc++.h>
using namespace std;
int a[101][101],m,n;
int main()
{
cin>>n>>m;
a[2][1]=1;
a[n][1]=1;
for(int j=2;j<=m;j++)
for(int i=1;i<=n;i++)
{
if(i==1)
a[i][j]=a[n][j-1]+a[i+1][j-1];
else
if(i==n)
a[i][j]=a[i-1][j-1]+a[1][j-1];
else
a[i][j]=a[i-1][j-1]+a[i+1][j-1];
}
cout<<a[1][m]<<endl;
return 0;
}
```
by joe_001 @ 2024-01-29 10:42:25