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标题:请问如何用java实现单链表的倒置。
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bobog
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已结贴  问题点数:20 回复次数:6 
请问如何用java实现单链表的倒置。
请问如何用java实现单链表的倒置。
我是新建一个链表,然后删了原来的链表的第一个节点,然后加到新链表去,然后再删第二个,然后再加到新的去。。。。这样循环直到加完为止,请问代码如何实现呢?
关于链表的各种申明,能不能请高手指点下?比如我想知道头节点如何表示等等。。。

麻烦了。。。
搜索更多相关主题的帖子: java 单链 倒置 
2010-04-23 20:56
lampeter123
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得分:10 
程序代码:
package java.util;


public class LinkedList<E>
    extends AbstractSequentialList<E>
    implements List<E>, Deque<E>, Cloneable, {
    private transient Entry<E> header = new Entry<E>(null, null, null);
    private transient int size = 0;

    /**
     * Constructs an empty list.
     */
    public LinkedList() {
        header.next = header.previous = header;
    }

    public LinkedList(Collection<? extends E> c) {
    this();
    addAll(c);
    }

    public E getFirst() {
    if (size==0)
        throw new NoSuchElementException();

    return header.next.element;
    }

    public E getLast()  {
    if (size==0)
        throw new NoSuchElementException();

    return header.previous.element;
    }

    public E removeFirst() {
    return remove(header.next);
    }

    public E removeLast() {
    return remove(header.previous);
    }

    /**
     * Inserts the specified element at the beginning of this list.
     *
     * @param e the element to add
     */
    public void addFirst(E e) {
    addBefore(e, header.next);
    }

    /**
     * Appends the specified element to the end of this list.
     *
     * <p>This method is equivalent to {@link #add}.
     *
     * @param e the element to add
     */
    public void addLast(E e) {
    addBefore(e, header);
    }

    /**
     * Returns <tt>true</tt> if this list contains the specified element.
     * More formally, returns <tt>true</tt> if and only if this list contains
     * at least one element <tt>e</tt> such that
     * <tt>(o==null&nbsp;?&nbsp;e==null&nbsp;:&nbsp;o.equals(e))</tt>.
     *
     * @param o element whose presence in this list is to be tested
     * @return <tt>true</tt> if this list contains the specified element
     */
    public boolean contains(Object o) {
        return indexOf(o) != -1;
    }

    /**
     * Returns the number of elements in this list.
     *
     * @return the number of elements in this list
     */
    public int size() {
    return size;
    }

    /**
     * Appends the specified element to the end of this list.
     *
     * <p>This method is equivalent to {@link #addLast}.
     *
     * @param e element to be appended to this list
     * @return <tt>true</tt> (as specified by {@link Collection#add})
     */
    public boolean add(E e) {
    addBefore(e, header);
        return true;
    }

    /**
     * Removes the first occurrence of the specified element from this list,
     * if it is present.  If this list does not contain the element, it is
     * unchanged.  More formally, removes the element with the lowest index
     * <tt>i</tt> such that
     * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>
     * (if such an element exists).  Returns <tt>true</tt> if this list
     * contained the specified element (or equivalently, if this list
     * changed as a result of the call).
     *
     * @param o element to be removed from this list, if present
     * @return <tt>true</tt> if this list contained the specified element
     */
    public boolean remove(Object o) {
        if (o==null) {
            for (Entry<E> e = header.next; e != header; e = e.next) {
                if (e.element==null) {
                    remove(e);
                    return true;
                }
            }
        } else {
            for (Entry<E> e = header.next; e != header; e = e.next) {
                if (o.equals(e.element)) {
                    remove(e);
                    return true;
                }
            }
        }
        return false;
    }

    /**
     * Appends all of the elements in the specified collection to the end of
     * this list, in the order that they are returned by the specified
     * collection's iterator.  The behavior of this operation is undefined if
     * the specified collection is modified while the operation is in
     * progress.  (Note that this will occur if the specified collection is
     * this list, and it's nonempty.)
     *
     * @param c collection containing elements to be added to this list
     * @return <tt>true</tt> if this list changed as a result of the call
     * @throws NullPointerException if the specified collection is null
     */
    public boolean addAll(Collection<? extends E> c) {
        return addAll(size, c);
    }

    /**
     * Inserts all of the elements in the specified collection into this
     * list, starting at the specified position.  Shifts the element
     * currently at that position (if any) and any subsequent elements to
     * the right (increases their indices).  The new elements will appear
     * in the list in the order that they are returned by the
     * specified collection's iterator.
     *
     * @param index index at which to insert the first element
     *              from the specified collection
     * @param c collection containing elements to be added to this list
     * @return <tt>true</tt> if this list changed as a result of the call
     * @throws IndexOutOfBoundsException {@inheritDoc}
     * @throws NullPointerException if the specified collection is null
     */
    public boolean addAll(int index, Collection<? extends E> c) {
        if (index < 0 || index > size)
            throw new IndexOutOfBoundsException("Index: "+index+
                                                ", Size: "+size);
        Object[] a = c.toArray();
        int numNew = a.length;
        if (numNew==0)
            return false;
    modCount++;

        Entry<E> successor = (index==size ? header : entry(index));
        Entry<E> predecessor = successor.previous;
    for (int i=0; i<numNew; i++) {
            Entry<E> e = new Entry<E>((E)a[i], successor, predecessor);
            predecessor.next = e;
            predecessor = e;
        }
        successor.previous = predecessor;

        size += numNew;
        return true;
    }

    /**
     * Removes all of the elements from this list.
     */
    public void clear() {
        Entry<E> e = header.next;
        while (e != header) {
            Entry<E> next = e.next;
            e.next = e.previous = null;
            e.element = null;
            e = next;
        }
        header.next = header.previous = header;
        size = 0;
    modCount++;
    }


    // Positional Access Operations

    /**
     * Returns the element at the specified position in this list.
     *
     * @param index index of the element to return
     * @return the element at the specified position in this list
     * @throws IndexOutOfBoundsException {@inheritDoc}
     */
    public E get(int index) {
        return entry(index).element;
    }

    /**
     * Replaces the element at the specified position in this list with the
     * specified element.
     *
     * @param index index of the element to replace
     * @param element element to be stored at the specified position
     * @return the element previously at the specified position
     * @throws IndexOutOfBoundsException {@inheritDoc}
     */
    public E set(int index, E element) {
        Entry<E> e = entry(index);
        E oldVal = e.element;
        e.element = element;
        return oldVal;
    }

    /**
     * Inserts the specified element at the specified position in this list.
     * Shifts the element currently at that position (if any) and any
     * subsequent elements to the right (adds one to their indices).
     *
     * @param index index at which the specified element is to be inserted
     * @param element element to be inserted
     * @throws IndexOutOfBoundsException {@inheritDoc}
     */
    public void add(int index, E element) {
        addBefore(element, (index==size ? header : entry(index)));
    }

    /**
     * Removes the element at the specified position in this list.  Shifts any
     * subsequent elements to the left (subtracts one from their indices).
     * Returns the element that was removed from the list.
     *
     * @param index the index of the element to be removed
     * @return the element previously at the specified position
     * @throws IndexOutOfBoundsException {@inheritDoc}
     */
    public E remove(int index) {
        return remove(entry(index));
    }

    /**
     * Returns the indexed entry.
     */
    private Entry<E> entry(int index) {
        if (index < 0 || index >= size)
            throw new IndexOutOfBoundsException("Index: "+index+
                                                ", Size: "+size);
        Entry<E> e = header;
        if (index < (size >> 1)) {
            for (int i = 0; i <= index; i++)
                e = e.next;
        } else {
            for (int i = size; i > index; i--)
                e = e.previous;
        }
        return e;
    }


    // Search Operations

    /**
     * Returns the index of the first occurrence of the specified element
     * in this list, or -1 if this list does not contain the element.
     * More formally, returns the lowest index <tt>i</tt> such that
     * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>,
     * or -1 if there is no such index.
     *
     * @param o element to search for
     * @return the index of the first occurrence of the specified element in
     *         this list, or -1 if this list does not contain the element
     */
    public int indexOf(Object o) {
        int index = 0;
        if (o==null) {
            for (Entry e = header.next; e != header; e = e.next) {
                if (e.element==null)
                    return index;
                index++;
            }
        } else {
            for (Entry e = header.next; e != header; e = e.next) {
                if (o.equals(e.element))
                    return index;
                index++;
            }
        }
        return -1;
    }

    /**
     * Returns the index of the last occurrence of the specified element
     * in this list, or -1 if this list does not contain the element.
     * More formally, returns the highest index <tt>i</tt> such that
     * <tt>(o==null&nbsp;?&nbsp;get(i)==null&nbsp;:&nbsp;o.equals(get(i)))</tt>,
     * or -1 if there is no such index.
     *
     * @param o element to search for
     * @return the index of the last occurrence of the specified element in
     *         this list, or -1 if this list does not contain the element
     */
    public int lastIndexOf(Object o) {
        int index = size;
        if (o==null) {
            for (Entry e = header.previous; e != header; e = e.previous) {
                index--;
                if (e.element==null)
                    return index;
            }
        } else {
            for (Entry e = header.previous; e != header; e = e.previous) {
                index--;
                if (o.equals(e.element))
                    return index;
            }
        }
        return -1;
    }

    // Queue operations.

    /**
     * Retrieves, but does not remove, the head (first element) of this list.
     * @return the head of this list, or <tt>null</tt> if this list is empty
     * @since 1.5
     */
    public E peek() {
        if (size==0)
            return null;
        return getFirst();
    }

    /**
     * Retrieves, but does not remove, the head (first element) of this list.
     * @return the head of this list
     * @throws NoSuchElementException if this list is empty
     * @since 1.5
     */
    public E element() {
        return getFirst();
    }

    /**
     * Retrieves and removes the head (first element) of this list
     * @return the head of this list, or <tt>null</tt> if this list is empty
     * @since 1.5
     */
    public E poll() {
        if (size==0)
            return null;
        return removeFirst();
    }

    /**
     * Retrieves and removes the head (first element) of this list.
     *
     * @return the head of this list
     * @throws NoSuchElementException if this list is empty
     * @since 1.5
     */
    public E remove() {
        return removeFirst();
    }

    /**
     * Adds the specified element as the tail (last element) of this list.
     *
     * @param e the element to add
     * @return <tt>true</tt> (as specified by {@link Queue#offer})
     * @since 1.5
     */
    public boolean offer(E e) {
        return add(e);
    }

    // Deque operations
    /**
     * Inserts the specified element at the front of this list.
     *
     * @param e the element to insert
     * @return <tt>true</tt> (as specified by {@link Deque#offerFirst})
     * @since 1.6
     */
    public boolean offerFirst(E e) {
        addFirst(e);
        return true;
    }

    /**
     * Inserts the specified element at the end of this list.
     *
     * @param e the element to insert
     * @return <tt>true</tt> (as specified by {@link Deque#offerLast})
     * @since 1.6
     */
    public boolean offerLast(E e) {
        addLast(e);
        return true;
    }

    /**
     * Retrieves, but does not remove, the first element of this list,
     * or returns <tt>null</tt> if this list is empty.
     *
     * @return the first element of this list, or <tt>null</tt>
     *         if this list is empty
     * @since 1.6
     */
    public E peekFirst() {
        if (size==0)
            return null;
        return getFirst();
    }

    /**
     * Retrieves, but does not remove, the last element of this list,
     * or returns <tt>null</tt> if this list is empty.
     *
     * @return the last element of this list, or <tt>null</tt>
     *         if this list is empty
     * @since 1.6
     */
    public E peekLast() {
        if (size==0)
            return null;
        return getLast();
    }

    /**
     * Retrieves and removes the first element of this list,
     * or returns <tt>null</tt> if this list is empty.
     *
     * @return the first element of this list, or <tt>null</tt> if
     *     this list is empty
     * @since 1.6
     */
    public E pollFirst() {
        if (size==0)
            return null;
        return removeFirst();
    }

    /**
     * Retrieves and removes the last element of this list,
     * or returns <tt>null</tt> if this list is empty.
     *
     * @return the last element of this list, or <tt>null</tt> if
     *     this list is empty
     * @since 1.6
     */
    public E pollLast() {
        if (size==0)
            return null;
        return removeLast();
    }

    /**
     * Pushes an element onto the stack represented by this list.  In other
     * words, inserts the element at the front of this list.
     *
     * <p>This method is equivalent to {@link #addFirst}.
     *
     * @param e the element to push
     * @since 1.6
     */
    public void push(E e) {
        addFirst(e);
    }

    /**
     * Pops an element from the stack represented by this list.  In other
     * words, removes and returns the first element of this list.
     *
     * <p>This method is equivalent to {@link #removeFirst()}.
     *
     * @return the element at the front of this list (which is the top
     *         of the stack represented by this list)
     * @throws NoSuchElementException if this list is empty
     * @since 1.6
     */
    public E pop() {
        return removeFirst();
    }

    /**
     * Removes the first occurrence of the specified element in this
     * list (when traversing the list from head to tail).  If the list
     * does not contain the element, it is unchanged.
     *
     * @param o element to be removed from this list, if present
     * @return <tt>true</tt> if the list contained the specified element
     * @since 1.6
     */
    public boolean removeFirstOccurrence(Object o) {
        return remove(o);
    }

    /**
     * Removes the last occurrence of the specified element in this
     * list (when traversing the list from head to tail).  If the list
     * does not contain the element, it is unchanged.
     *
     * @param o element to be removed from this list, if present
     * @return <tt>true</tt> if the list contained the specified element
     * @since 1.6
     */
    public boolean removeLastOccurrence(Object o) {
        if (o==null) {
            for (Entry<E> e = header.previous; e != header; e = e.previous) {
                if (e.element==null) {
                    remove(e);
                    return true;
                }
            }
        } else {
            for (Entry<E> e = header.previous; e != header; e = e.previous) {
                if (o.equals(e.element)) {
                    remove(e);
                    return true;
                }
            }
        }
        return false;
    }

    /**
     * Returns a list-iterator of the elements in this list (in proper
     * sequence), starting at the specified position in the list.
     * Obeys the general contract of <tt>List.listIterator(int)</tt>.<p>
     *
     * The list-iterator is <i>fail-fast</i>: if the list is structurally
     * modified at any time after the Iterator is created, in any way except
     * through the list-iterator's own <tt>remove</tt> or <tt>add</tt>
     * methods, the list-iterator will throw a
     * <tt>ConcurrentModificationException</tt>.  Thus, in the face of
     * concurrent modification, the iterator fails quickly and cleanly, rather
     * than risking arbitrary, non-deterministic behavior at an undetermined
     * time in the future.
     *
     * @param index index of the first element to be returned from the
     *              list-iterator (by a call to <tt>next</tt>)
     * @return a ListIterator of the elements in this list (in proper
     *         sequence), starting at the specified position in the list
     * @throws IndexOutOfBoundsException {@inheritDoc}
     * @see List#listIterator(int)
     */
    public ListIterator<E> listIterator(int index) {
    return new ListItr(index);
    }

    private class ListItr implements ListIterator<E> {
    private Entry<E> lastReturned = header;
    private Entry<E> next;
    private int nextIndex;
    private int expectedModCount = modCount;

    ListItr(int index) {
        if (index < 0 || index > size)
        throw new IndexOutOfBoundsException("Index: "+index+
                            ", Size: "+size);
        if (index < (size >> 1)) {
        next = header.next;
        for (nextIndex=0; nextIndex<index; nextIndex++)
            next = next.next;
        } else {
        next = header;
        for (nextIndex=size; nextIndex>index; nextIndex--)
            next = next.previous;
        }
    }

    public boolean hasNext() {
        return nextIndex != size;
    }

    public E next() {
        checkForComodification();
        if (nextIndex == size)
        throw new NoSuchElementException();

        lastReturned = next;
        next = next.next;
        nextIndex++;
        return lastReturned.element;
    }

    public boolean hasPrevious() {
        return nextIndex != 0;
    }

    public E previous() {
        if (nextIndex == 0)
        throw new NoSuchElementException();

        lastReturned = next = next.previous;
        nextIndex--;
        checkForComodification();
        return lastReturned.element;
    }

    public int nextIndex() {
        return nextIndex;
    }

    public int previousIndex() {
        return nextIndex-1;
    }

    public void remove() {
            checkForComodification();
            Entry<E> lastNext = lastReturned.next;
            try {
                LinkedList.this.remove(lastReturned);
            } catch (NoSuchElementException e) {
                throw new IllegalStateException();
            }
        if (next==lastReturned)
                next = lastNext;
            else
        nextIndex--;
        lastReturned = header;
        expectedModCount++;
    }

    public void set(E e) {
        if (lastReturned == header)
        throw new IllegalStateException();
        checkForComodification();
        lastReturned.element = e;
    }

    public void add(E e) {
        checkForComodification();
        lastReturned = header;
        addBefore(e, next);
        nextIndex++;
        expectedModCount++;
    }

    final void checkForComodification() {
        if (modCount != expectedModCount)
        throw new ConcurrentModificationException();
    }
    }

    private static class Entry<E> {
    E element;
    Entry<E> next;
    Entry<E> previous;

    Entry(E element, Entry<E> next, Entry<E> previous) {
        this.element = element;
        this.next = next;
        this.previous = previous;
    }
    }

    private Entry<E> addBefore(E e, Entry<E> entry) {
    Entry<E> newEntry = new Entry<E>(e, entry, entry.previous);
    newEntry.previous.next = newEntry;
    newEntry.next.previous = newEntry;
    size++;
    modCount++;
    return newEntry;
    }

    private E remove(Entry<E> e) {
    if (e == header)
        throw new NoSuchElementException();

        E result = e.element;
    e.previous.next = e.next;
    e.next.previous = e.previous;
        e.next = e.previous = null;
        e.element = null;
    size--;
    modCount++;
        return result;
    }

    /**
     * @since 1.6
     */
    public Iterator<E> descendingIterator() {
        return new DescendingIterator();
    }

    /** Adapter to provide descending iterators via ListItr.previous */
    private class DescendingIterator implements Iterator {
        final ListItr itr = new ListItr(size());
    public boolean hasNext() {
        return itr.hasPrevious();
    }
    public E next() {
            return itr.previous();
        }
    public void remove() {
            itr.remove();
        }
    }

    /**
     * Returns a shallow copy of this <tt>LinkedList</tt>. (The elements
     * themselves are not cloned.)
     *
     * @return a shallow copy of this <tt>LinkedList</tt> instance
     */
    public Object clone() {
        LinkedList<E> clone = null;
    try {
        clone = (LinkedList<E>) super.clone();
    } catch (CloneNotSupportedException e) {
        throw new InternalError();
    }

        // Put clone into "virgin" state
        clone.header = new Entry<E>(null, null, null);
        clone.header.next = clone.header.previous = clone.header;
        clone.size = 0;
        clone.modCount = 0;

        // Initialize clone with our elements
        for (Entry<E> e = header.next; e != header; e = e.next)
            clone.add(e.element);

        return clone;
    }

    /**
     * Returns an array containing all of the elements in this list
     * in proper sequence (from first to last element).
     *
     * <p>The returned array will be "safe" in that no references to it are
     * maintained by this list.  (In other words, this method must allocate
     * a new array).  The caller is thus free to modify the returned array.
     *
     * <p>This method acts as bridge between array-based and collection-based
     * APIs.
     *
     * @return an array containing all of the elements in this list
     *         in proper sequence
     */
    public Object[] toArray() {
    Object[] result = new Object[size];
        int i = 0;
        for (Entry<E> e = header.next; e != header; e = e.next)
            result[i++] = e.element;
    return result;
    }

    /**
     * Returns an array containing all of the elements in this list in
     * proper sequence (from first to last element); the runtime type of
     * the returned array is that of the specified array.  If the list fits
     * in the specified array, it is returned therein.  Otherwise, a new
     * array is allocated with the runtime type of the specified array and
     * the size of this list.
     *
     * <p>If the list fits in the specified array with room to spare (i.e.,
     * the array has more elements than the list), the element in the array
     * immediately following the end of the list is set to <tt>null</tt>.
     * (This is useful in determining the length of the list <i>only</i> if
     * the caller knows that the list does not contain any null elements.)
     *
     * <p>Like the {@link #toArray()} method, this method acts as bridge between
     * array-based and collection-based APIs.  Further, this method allows
     * precise control over the runtime type of the output array, and may,
     * under certain circumstances, be used to save allocation costs.
     *
     * <p>Suppose <tt>x</tt> is a list known to contain only strings.
     * The following code can be used to dump the list into a newly
     * allocated array of <tt>String</tt>:
     *
     * <pre>
     *     String[] y = x.toArray(new String[0]);</pre>
     *
     * Note that <tt>toArray(new Object[0])</tt> is identical in function to
     * <tt>toArray()</tt>.
     *
     * @param a the array into which the elements of the list are to
     *          be stored, if it is big enough; otherwise, a new array of the
     *          same runtime type is allocated for this purpose.
     * @return an array containing the elements of the list
     * @throws ArrayStoreException if the runtime type of the specified array
     *         is not a supertype of the runtime type of every element in
     *         this list
     * @throws NullPointerException if the specified array is null
     */
    public <T> T[] toArray(T[] a) {
        if (a.length < size)
            a = (T[])java.lang.reflect.Array.newInstance(
                                a.getClass().getComponentType(), size);
        int i = 0;
    Object[] result = a;
        for (Entry<E> e = header.next; e != header; e = e.next)
            result[i++] = e.element;

        if (a.length > size)
            a[size] = null;

        return a;
    }

    private static final long serialVersionUID = 876323262645176354L;

    /**
     * Save the state of this <tt>LinkedList</tt> instance to a stream (that
     * is, serialize it).
     *
     * @serialData The size of the list (the number of elements it
     *             contains) is emitted (int), followed by all of its
     *             elements (each an Object) in the proper order.
     */
    private void writeObject( s)
        throws  {
    // Write out any hidden serialization magic
    s.defaultWriteObject();

        // Write out size
        s.writeInt(size);

    // Write out all elements in the proper order.
        for (Entry e = header.next; e != header; e = e.next)
            s.writeObject(e.element);
    }

    /**
     * Reconstitute this <tt>LinkedList</tt> instance from a stream (that is
     * deserialize it).
     */
    private void readObject( s)
        throws , ClassNotFoundException {
    // Read in any hidden serialization magic
    s.defaultReadObject();

        // Read in size
        int size = s.readInt();

        // Initialize header
        header = new Entry<E>(null, null, null);
        header.next = header.previous = header;

    // Read in all elements in the proper order.
    for (int i=0; i<size; i++)
            addBefore((E)s.readObject(), header);
    }
}

你的优秀和我的人生无关!!!!
    
    我要过的,是属于我自己的生活~~~
2010-04-23 22:59
lampeter123
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有时间看看JDK的源码也不错,其实JAVA已将数据结构封装好,拿来就用吧

你的优秀和我的人生无关!!!!
    
    我要过的,是属于我自己的生活~~~
2010-04-23 23:01
linjx0123
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如楼上所讲,链表在java的api中已经实现。

链表的倒置,你所讲的算法不是最优的,最优的算法应该是把指针反转。如下表示
a->b->c->d 倒置为 a<-b<-c<-d, 然后把头节点指向d。

为了让你更容易理解数据结构中链表的操作,举个简单例子如下:(注:严密全面的单链表比下面的例子复杂,建议看看java数据结构的书中关于链表的描述,希望下面的例子能对你有所帮助。还有可以参考c语言中数据结构的实现,能让你对数据结构理解的更深)
程序代码:
public class LinkList {
    public int size;
    public Node head;
    private Node last;
    public LinkList(){
        size=0;
        head=null;
        last=head;
    }
   
    //添加新节点
    public void addNode(Node node){
        if(size==0){
            head=node;
            last=node;
        }else{
            last.next=node;
            last=node;
        }
        size++;
    }
   
    //根据给定的数组创建单链表
    public void createLinkByInt(int[] element){
        for(int i=0;i<element.length;i++){
            addNode(new Node(element[i],null));
        }
    }
   
    //反转
    public void reverse(){
        Node node = head;
        Node newNode = null;
        Node temp = null;
        for(int i=0;i<size;i++){
            temp = node.next;//保存下一个节点给temp
            node.next = newNode;//将当前的节点指向新节点
            newNode = node;//新节点等于当前的节点
            node = temp;//当前节点指向原来链表的下一个节点。
        }
        head=newNode;//链表的头指针指向原来链表的最后一个节点
    }
   
    //输出链表
    public void printLink(){
        Node node = head;
        for(int i=0;i<size;i++){
            if(i!=0)
                node=node.next;
            System.out.println(node.element);           
        }
    }
   
    public static void main(String[] args){
        LinkList ll = new LinkList();
        int[] e = {1,2,3,4,5,6};
        ll.createLinkByInt(e);
        ll.printLink();
        ll.reverse();
        ll.printLink();
    }
}

class Node{
    public Node next;
    public Object element;
    public Node(Object element,Node next){
        this.next=next;
        this.element=element;
    }
}


 
2010-04-24 20:35
bobog
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回复 4楼 linjx0123
你好,非常感谢你的回帖,我有些地方不明白。 你不是说把指针反转吗? 那为什么输出的是一个顺序的,一个倒序的呢?
2010-05-05 09:03
linjx0123
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回复 5楼 bobog
因为反转了呀。反转了就是倒序.没反转前是正序的.
2010-05-06 12:07
zaiwuyuan
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首先建立一个包dataStrucuture.LinearList存放这两个类和一个接口,这里的代码包括一个实例方法!
package dataStructure.linearList;
public interface LList<E> {
    boolean isEmpty();
    int length();
    E get(int index);
    E set(int index,E element);
    boolean add(int index,E element);
    boolean add(E element);
    E remove(int index);
    void clear();
}
package dataStructure.linearList;
public class Node<E> {
    public E data;
    public Node<E> next;
    public Node(E data,Node<E> next)
    {
        this.data=data;
        this.next=next;
    }
    public Node(E data)
    {
        this(data, null);
    }
    public Node()
    {
        this(null,null);
    }
}
package dataStructure.linearList;
import dataStructure.linearList.Node;
public class SinglyLinkedList<E> implements LList<E>{
    protected Node<E> head;
    public SinglyLinkedList()
    {
        this.head=null;
    }
    public SinglyLinkedList(Node<E> head)
    {
        this.head=head;
    }
    public boolean isEmpty()
    {
        return this.head==null;
    }
    public  int length()
    {
        Node<E> p=this.head;
        int i=0;
        while(p!=null)
        {
            i++;
            p=p.next;
        }
        return i;
    }
    public E get(int index)
    {
        if(this.head!=null&&index>=0)
        {
            int j=0;
            Node<E> p=this.head;
            while(p!=null&&j<index)
            {
                j++;
                p=p.next;
            }
            if(p!=null)
                return (E)p.data;
        }
        return null;
    }
    public E set(int index,E element)
    {
        if(this.head!=null&&index>=0&&element!=null)
        {
            int j=0;
            Node<E> p=this.head;
            while(p!=null&&j<index)
            {
                j++;
                p=p.next;
            }
            if(p!=null)
            {
                E old=(E)p.data;
                p.data=element;
                return old;
            }
        }
        return null;
    }
    public boolean add(int index,E element)
    {
        if(element==null)
            return false;
        if(this.head==null||index<=0)
        {
            Node<E> q=new Node<E>(element);
            q.next=this.head;
            this.head=q;
        }
        else
        {
            int j=0;
            Node<E> p=this.head;
            while(p.next!=null&&j<index-1)
            {
                j++;
                p=p.next;
            }
            Node<E> q=new Node<E>(element);
            q.next=p.next;
            p.next=q;
        }
        return true;
    }
   
    public boolean add(E element)
    {
        return add(Integer.MAX_VALUE,element);
    }
    public E remove(int index)
    {
        E old=null;
        if(this.head!=null&&index>=0)
        {
            if(index==0)
            {
                old=(E)this.head.data;
                this.head=this.head.next;
            }
            else
            {
                int j=0;
                Node<E> p=this.head;
                while(p.next!=null&&j<index-1)
                {
                    j++;
                    p=p.next;
                }
                if(p.next!=null)
                {
                    old=(E)p.next.data;
                    p.next=(p.next).next;
                }
            }
        }
        return old;
    }
    public void clear()
    {
        this.head=null;
    }
    public String toString()
    {
        String str="(";
        Node<E> p=this.head;
        while(p!=null)
        {
            str+=p.data.toString();
            p=p.next;
            if(p!=null)
                str+=",";
        }
        return str+")";
    }
}
然后再别的文件夹下打个类就可以了!
package Array;
import dataStructure.linearList.SinglyLinkedList;
import dataStructure.linearList.Node;
public class R<E>extends SinglyLinkedList {
    public R()
    {
        super();
    }
    public void reverse()
    {
        Node<E> p=this.head,q=null,front=null;
        while(p!=null)
        {
            q=p.next;
            p.next=front;
            front=p;
            p=q;
        }
        this.head=front;
    }
    public static void main(String[] args)
    {
        R<Integer> list=new R<Integer>();
        for(int i=0;i<6;i++)
        {
            list.add(0,new Integer(i));
        }
        System.out.print("原链表"+list.toString());
        list.reverse();
        System.out.print("逆转后"+list.toString());
    }
}
2010-05-09 12:15
快速回复:请问如何用java实现单链表的倒置。
数据加载中...
 
   



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