DFS for some random struct.

DFS.go

func (bon* BONode) partition() ([]*BONode, []*BONode) {
	// Partition a node, yielding her rank 0 children and rank >0 children.
	// This should take O(logn) time, because every node except the root has at most 2 children, which one of those children has rank 0.

	nodestack := make([]*BONode, 10)  // this is to be used as stack
	nodestack = appendList(nodestack, bon.children_head)

	zeros := make([]*BONode, 10)
	nonzeros := make([]*BONode, 10)

	for len(nodestack) != 0 {
		poppednode := nodestack[len(nodestack)-1]; nodestack = nodestack[0:len(nodestack)]  // pop from stack

		if poppednode.rank == 0 {
			zeros = append(zeros, poppednode)
		} else {
			nonzeros = append(nonzeros, poppednode)
		}
		appendList(nodestack, poppednode.children_head)
	}
	return zeros, nonzeros
}