直接动态规划o(nm)

f[i][j] = f[i - 1][j] + f[i][j - 1]， 当i，j不同时为奇数时;

#include <iostream>

using namespace std;
int f[35][35];
int main(){
    int n, m;
    cin >> n >> m;
    f[0][1] = 1;
    for (int i = 1; i <= n; i ++){
        for (int j = 1; j <= m; j++){
            if (j & 1 | i & 1)
                f[i][j] = f[i - 1][j] + f[i][j - 1];
        }
    }
    cout << f[n][m] << endl;
    return 0;
}