Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;
import java.util.Collection;
import java.util.Comparator;

import java.util.Iterator;

import java.util.SortedSet;

public class Main {
    public static boolean containsAll(Collection a, Collection b) {
        // fast paths
        if (a == b)
            return true;
        if (b.size() == 0)
            return true;
        if (a.size() < b.size())
            return false;

        if (a instanceof SortedSet && b instanceof SortedSet) {
            SortedSet aa = (SortedSet) a;
            SortedSet bb = (SortedSet) b;
            Comparator bbc = bb.comparator();
            Comparator aac = aa.comparator();
            if (bbc == null && aac == null) {
                Iterator ai = aa.iterator();
                Iterator bi = bb.iterator();
                Comparable ao = (Comparable) ai.next(); // these are ok, since the sizes are != 0
                Comparable bo = (Comparable) bi.next();
                while (true) {
                    int rel = ao.compareTo(bo);
                    if (rel == 0) {
                        if (!bi.hasNext())
                            return true;
                        if (!ai.hasNext())
                            return false;
                        bo = (Comparable) bi.next();
                        ao = (Comparable) ai.next();
                    } else if (rel < 0) {
                        if (!ai.hasNext())
                            return false;
                        ao = (Comparable) ai.next();
                    } else {
                        return false;
                    }
                }
            } else if (bbc.equals(aac)) {
                Iterator ai = aa.iterator();
                Iterator bi = bb.iterator();
                Object ao = ai.next(); // these are ok, since the sizes are != 0
                Object bo = bi.next();
                while (true) {
                    int rel = aac.compare(ao, bo);
                    if (rel == 0) {
                        if (!bi.hasNext())
                            return true;
                        if (!ai.hasNext())
                            return false;
                        bo = bi.next();
                        ao = ai.next();
                    } else if (rel < 0) {
                        if (!ai.hasNext())
                            return false;
                        ao = ai.next();
                    } else {
                        return false;
                    }
                }
            }
        }
        return a.containsAll(b);
    }

    /**
     * Get the size of an iterator (number of items in it).
     * @param source
     * @return
     */
    public static int size(Iterator source) {
        int result = 0;
        while (source.hasNext()) {
            source.next();
            ++result;
        }
        return result;
    }
}