// Works by calling private insertion method
public boolean insert(Point pt) {
if (pt == null) return false;
// Tree is empty
if (root == null) {
root = new TreeNode(pt);
root.cd = true;
size++;
return true;
} else return insert(root, null, new TreeNode(pt), true, true);
}
/**
* Private method created for inserting into the tree. Works recursively returns false if point
* already in tree Method for inserting a node into the tree. Works by traversing through the
* tree, branches off x value for even cuts, and y for odd cuts. Uses other value as a tie
* breaker. Also keeps track of height and size for constant return time on those function calls.
*/
private boolean insert(TreeNode t, TreeNode prev, TreeNode newNode, boolean cd, boolean left) {
if (t == null) { // Found where node should live
if (left) {
prev.left = newNode;
} else {
prev.right = newNode;
}
newNode.cd = cd;
newNode.parent = prev;
size++;
return true;
} else if (t.p.equals(newNode.p)) return false; // Found the point, don't insert it
// Recursive calls to left or right tree
else if (cd) {
if (newNode.p.x() < t.p.x()) insert(t.left, t, newNode, !cd, true);
else if (newNode.p.x() > t.p.x()) insert(t.right, t, newNode, !cd, false);
else { // Tie breaker
if (newNode.p.y() < t.p.y()) insert(t.left, t, newNode, !cd, true);
else insert(t.right, t, newNode, !cd, false);
}
} else {
if (newNode.p.y() < t.p.y()) insert(t.left, t, newNode, !cd, true);
else if (newNode.p.y() > t.p.y()) insert(t.right, t, newNode, !cd, false);
else { // Tie breaker
if (newNode.p.x() < t.p.x()) insert(t.left, t, newNode, !cd, true);
else insert(t.right, t, newNode, !cd, false);
}
}
updateMinMax(t, newNode);
t.height = maxHeight(t.left, t.right) + 1;
// Now check if tree became unbalanced
if (unbalanced(t)) {
// System.out.println("unbalanced");
Point[] points = collectSatanSpawn(t);
TDTree newSubTree = new TDTree(points, cd);
swapDataMembers(t, newSubTree.root);
}
return true;
} // End private insert() method