SplayDelete.java

/*******************************************************************************
 * Copyright (c) 2012-present Jakub Kováč, Jozef Brandýs, Katarína Kotrlová,
 * Pavol Lukča, Ladislav Pápay, Viktor Tomkovič, Tatiana Tóthová
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ******************************************************************************/
package algvis.ds.dictionaries.splaytree;

import algvis.core.Node;
import algvis.core.NodeColor;
import algvis.core.visual.ZDepth;

public class SplayDelete extends SplayAlg {
    private final int K;

    public SplayDelete(SplayTree T, int x) {
        super(T, x);
        K = x;
    }

    @Override
    public void runAlgorithm() {
        setHeader("delete", K);
        SplayNode s = new SplayNode(T, K, ZDepth.ACTIONNODE);
        s.setColor(NodeColor.DELETE);
        addToScene(s);
        if (T.getRoot() == null) {
            s.goToRoot();
            addStep("empty");
            pause();
            s.goDown();
            s.setColor(NodeColor.NOTFOUND);
            addStep("notfound");
            removeFromScene(s);
            return;
        }
        s.goAboveRoot();

        SplayNode w = find(K);

        if (w.getKey() != s.getKey()) {
            addStep("notfound");
            s.setColor(NodeColor.NOTFOUND);
            s.goDown();
            removeFromScene(s);
            splay(w);
            w.setColor(NodeColor.NORMAL);
            return;
        }
        w.setColor(NodeColor.DELETE);
        removeFromScene(s);
        splay(w);

        pause();
        addToScene(w);
        w.goDown();
        removeFromScene(w);
        if (w.getLeft() == null) {
            addStep("splaydeleteright");
            T.setRoot(w.getRight());
            T.getRoot().setParent(null);
            T.reposition();
            pause();
        } else if (w.getRight() == null) {
            addStep("splaydeleteleft");
            T.setRoot(w.getLeft());
            T.getRoot().setParent(null);
            T.reposition();
            pause();
        } else {
            addStep("splaydelete");
            T.setRoot2(w.getLeft());
            T.getRoot2().shiftTree(-75, 0);
            T.getRoot2().setParent(null);
            T.setRoot(w.getRight());
            T.getRoot().setParent(null);
            s = new SplayNode(T, -Node.INF, ZDepth.ACTIONNODE);
            s.setColor(NodeColor.FIND);
            addToScene(s);
            w = w.getRight();
            s.goTo(w);
            pause();
            while (w.getLeft() != null) {
                w = w.getLeft();
                s.goTo(w);
                pause();
            }
            w.setColor(NodeColor.FIND);
            removeFromScene(s);
            // splay TODO: shades
            // TODO: reuse splaying
            while (!w.isRoot()) {
                if (w.getParent().isRoot()) {
                    T.rotate2(w);
                    // setText ("splayroot");
                } else {
                    if (w.isLeft() == w.getParent().isLeft()) {
                        /*
                         * if (w.isLeft()) setText ("splayzigzigleft"); else
                         * setText ("splayzigzigright");
                         */
                        T.rotate2(w.getParent());
                        pause();
                        T.rotate2(w);
                    } else {
                        /*
                         * if (!w.isLeft()) setText ("splayzigzagleft"); else
                         * setText ("splayzigzagright");
                         */
                        T.rotate2(w);
                        pause();
                        T.rotate2(w);
                    }
                }
                pause();
            }
            addStep("splaydeletelink");
            T.setRoot(w);
            w.setColor(NodeColor.NORMAL);
            w.linkLeft(T.getRoot2());
            T.setRoot2(null);
            T.reposition();
            pause();
        }

        addNote("done");
    }
}