%--------------------------
 % @Author: Jingqiao Hu
 % @Date: 2021-06-16 16:05:00
 % @LastEditTime: 2021-06-16 16:24:09

 % return neighbor eles-id for all node-id
%--------------------------
function neid = nodes_eles_id(nelx, nely, P_num, microx)
    
    if P_num==0
        [~, ~, ~, ele_nodes_id] = forAssemble(nelx, nely);    
        nnodes = (nelx+1) *(nely+1);
    else
        [~, ~, ~, ele_nodes_id] = macro_edofMat_bezier(nelx, nely, P_num);
        border  = round(linspace(1, microx+1, 2)); 
        seg_num = length(border)-1; % segment num divided by added macro dofs
        var_num = P_num*seg_num;
        nnodes = (nelx+1)*(nely+1) + var_num*nely*(nelx+1) + var_num*nelx*(nely+1);
    end
    
    neid = cell(nnodes, 1); % maybe different node have different number of neighbor-ele
    for nid = 1:nnodes
        [r,~] = find(ele_nodes_id==nid);
        neid{nid} = r;
    end
end