Method deleteHelper

structure/tree/rbtree.go:300–350

(node *RBNode[T], key T)

}

func (t *RB[T]) deleteHelper(node *RBNode[T], key T) bool {
	z := t._NIL
	for node != t._NIL {
		switch {
		case node.key == key:
			z = node
			fallthrough
		case node.key <= key:
			node = node.right
		case node.key > key:
			node = node.left
		}
	}

	if z == t._NIL {
		return false
	}

	var x *RBNode[T]
	y := z
	yOriginColor := y.color
	if z.left == t._NIL {
		x = z.right
		t.transplant(z, z.right)
	} else if z.right == t._NIL {
		x = z.left
		t.transplant(z, z.left)
	} else {
		y = minimum[T](z.right, t._NIL).(*RBNode[T])
		yOriginColor = y.color
		x = y.right
		if y.parent == z {
			x.parent = y
		} else {
			t.transplant(y, y.right)
			y.right = z.right
			y.right.parent = y
		}

		t.transplant(z, y)
		y.left = z.left
		y.left.parent = y
		y.color = z.color
	}

	if yOriginColor == Black {
		t.deleteFix(x)
	}

	return true
}

func (t *RB[T]) deleteFix(x *RBNode[T]) {
	var s *RBNode[T]