“…c be a child of 1 c , 4 c be a child of 2 c , 8 c be a child of 4 c , 5 c be a child of 8 c , and for a child of 5 c , let j be the child of node i, as in the above search order, Because the search sequence according to the above discussion, it has a neighbor node logic is no subsequent child nodes, so that it does not have children, and then 3 c is a child of 1 c , is a child node, the same 7 c is a child of 3 c , 6 c and 7 c has no child nodes. If j is a child of node i ,then A defines the search number of the earliest node in the subtree of j that can be traced back to node i by non-parent-side edges (i and j sides).…”