Method rotateLeft

src/test/resources/pta/basic/RedBlackBST.java:195–204

(Node h)

    }

    private Node rotateLeft(Node h) {
        Node x = h.right;
        h.right = x.left;
        x.left = h;
        x.color = x.left.color;
        x.left.color = RED;
        x.size = h.size;
        h.size = size(h.left) + size(h.right) + 1;
        return x;
    }

    private void flipColors(Node h) {
        // h must have opposite color of its two children