无聊做了下算法题，用递归方法，不知道对不对

int fun(int a[3][4],int n,int m,int i,int j)
{
    int key = a[i][j];
    if(i +1 == n && j+1 == m) return key;
    int right = key;
    int down  = key;
    if(j+1<m) right += fun(a,n,m,i,j+1);
    if(i+1<n) down += fun(a,n,m,i+1,j);

    return right>down?right:down;
}


int main()
{
    int a[3][4] = {
     {2,5,6,4},
     {5,8,7,3},
     {9,5,1,4}
    };
    cout<<fun(a,3,4,0,0);

    return 0;
}