de.tum.in.naturals.unionfind.IntUnionFind Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of naturals-util Show documentation

Datastructures and utility classes for non-negative integers

The newest version!

/*
 * Copyright (C) 2017 Tobias Meggendorfer
 *
 * 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 .
 */

package de.tum.in.naturals.unionfind;

import java.util.function.IntUnaryOperator;

public interface IntUnionFind extends IntUnaryOperator {
    /**
     * Extends the size of the domain by 1 element.
     *
     * @throws UnsupportedOperationException
     *     if the {@code add} operation is not supported by this implementation.
     * @see #add(int)
     */
    default void add() {
        add(1);
    }

    /**
     * Extends the size of the domain by {@code num} elements (optional operation).
     *
     * @throws UnsupportedOperationException
     *     if the {@code add} operation is not supported by this implementation.
     */
    void add(int num);

    @Override
    default int applyAsInt(int operand) {
        return find(operand);
    }

    /**
     * Returns the number of components.
     */
    int componentCount();

    /**
     * Returns true if the two sites are in the same component.
     */
    default boolean connected(int p, int q) {
        return find(p) == find(q);
    }

    /**
     * Returns the component identifier for the component containing site {@code p}.
     */
    int find(int p);

    /**
     * Returns the number of elements in this union-find.
     */
    int size();

    /**
     * Merges the component containing site {@code p} with the component containing site {@code q}.
     */
    void union(int p, int q);
}