...

一个普通的题解

using namespace std;
int a[40][40];
int main() {
	
	
    int n, m; 
	cin >> n >> m;
	
    a[0][1] = 1;
	for(int i = 1; i <= m; i++) {
		for(int j = 1; j <= n; j++) {
			int l = j - 1;
			int r = j + 1;
			if(!l) l = n; 
			if(r == n + 1) r = 1; 
			a[i][j] = a[i-1][l] + a[i-1][r];
		}
	
    } 
	cout << a[m][1];  

	return 0;
}