Java单链表实现多项式相加、多种方式实现约瑟夫环

数据结构复习，代码是最好的说明。

多项式相加-单链表：

节点类：

public class Node implements Cloneable{    //系数、指数、下一个(前两者可用double)    private int coefficient;    private int exponent;    private Node next;    public Node(int coefficient, int exponent) {        this.coefficient = coefficient;        this.exponent = exponent;    }    public int getCoefficient() {        return coefficient;    }    public void setCoefficient(int coefficient) {        this.coefficient = coefficient;    }    public int getExponent() {        return exponent;    }    public void setExponent(int exponent) {        this.exponent = exponent;    }    public Node getNext() {        return next;    }    public void setNext(Node next) {        this.next = next;    }    /**     * 深拷贝     * @return     * @throws CloneNotSupportedException     */    @Override    public Object clone() throws CloneNotSupportedException {        Node node = null;        node = (Node) super.clone();        if (node.next!=null){            node.next = (Node) node.next.clone();        }        return node;    }}

单链表类：

public class SingleLinkedList implements Cloneable{    private Node head;    public SingleLinkedList(Node head) {        this.head = head;    }    /**     * 深拷贝     * @return     */    @Override    public Object clone(){        SingleLinkedList s = null;        try {            s = (SingleLinkedList) super.clone();            s.head = (Node) head.clone();        } catch (CloneNotSupportedException e) {            e.printStackTrace();        }        return s;    }    /**     * 多项式append，按指数从大到小排序     * @param coefficient     * @param exponent     */    public void append(int coefficient, int exponent){        if (coefficient==0){            return;        }        Node temp = head;        //头处理        if (exponent>head.getExponent()){            Node node = new Node(coefficient,exponent);            node.setNext(head);            head = node;            return;        }        //        while (temp.getNext()!=null){            if (exponent<temp.getExponent()&&exponent>temp.getNext().getExponent()){                Node node = new Node(coefficient,exponent);                node.setNext(temp.getNext());                temp.setNext(node);                return;            }else if (exponent==temp.getExponent()){                temp.setCoefficient(temp.getCoefficient()+coefficient);                return;            }            temp = temp.getNext();        }        //尾处理        if(exponent==temp.getExponent()){            temp.setCoefficient(temp.getCoefficient()+coefficient);            return;        }else if(exponent<temp.getExponent()){            Node node = new Node(coefficient,exponent);            temp.setNext(node);            return;        }    }    /**     * 打印     */    public void printAll(){        Node temp = head;        while (temp.getNext()!=null){            System.out.print(temp.getCoefficient()+"x^"+temp.getExponent()+(temp.getNext().getCoefficient()>0?"+":""));            temp = temp.getNext();        }        System.out.print(temp.getCoefficient()+"x^"+temp.getExponent());        System.out.println();    }    /**     * 多项式相加返回结果，用的深拷贝     * @param anotherSingleLinkedList     * @return     */    public SingleLinkedList add(SingleLinkedList anotherSingleLinkedList) {        SingleLinkedList result = (SingleLinkedList) anotherSingleLinkedList.clone();        Node temp = head;        while (temp.getNext()!=null){            result.append(temp.getCoefficient(),temp.getExponent());            temp = temp.getNext();        }        return result;    }    public static void main(String[] args) {        SingleLinkedList a=new SingleLinkedList(new Node(10,5));        a.append(10,4);        a.append(10,3);        a.append(10,2);        a.append(10,1);        SingleLinkedList b=new SingleLinkedList(new Node(-5,10));        b.append(-5,11);        b.append(-5,8);        b.append(-5,9);        b.append(-5,7);        b.append(-5,5);        System.out.println("相加之前：");        a.printAll();        b.printAll();        System.out.println("结果：");        a.add(b).printAll();        System.out.println("相加之后：");        a.printAll();        b.printAll();    }}

约瑟夫环-循环链表：

节点类：

public class Node {    private int num;    private Node next;    public Node(int num) {        this.num = num;    }    public int getNum() {        return num;    }    public void setNum(int num) {        this.num = num;    }    public Node getNext() {        return next;    }    public void setNext(Node next) {        this.next = next;    }}

主类：

public class Josehus {    /**     *     * @param n 一公多少人，例如8个人，则编号1-8号     * @param s 开始号码，例如1，则从1号开始报数     * @param m 指定号码，例如3，则报到3的人移除     */    public void josehus(int n,int s,int m){        //表头        Node head = new Node(1);        //pre为当前报数者的前继，使得变量最少        Node pre = null;        //初始化循环链表，help为辅助变量        Node help = head;        for (int i = 2; i <= n; i++) {            if (i==s){                pre = help;            }            help.setNext(new Node(i));            help = help.getNext();        }        help.setNext(head);        if (pre == null){            pre = help;        }        //开始报数，报到数则移除链表        int j = 0;        while (pre.getNum()!=pre.getNext().getNum()){            if(j == m-1){                System.out.print(pre.getNext().getNum()+"-");                pre.setNext(pre.getNext().getNext());                j = 0;                continue;            }else {                j++;            }            pre = pre.getNext();        }        System.out.print(pre.getNum());        System.out.println();    }    public static void main(String[] args) {        Josehus j=new Josehus();        j.josehus(8,1,3);    }}

约瑟夫环-数组：

public void josehus(int n,int s,int m){    int [] array = new int[n];    for (int i = 0; i < n; i++)        array[i] = i+1;    int count = 0;    int num = n;    //两层循环,相当于一个n*n的遍历    while (num > 0) {        for (int i = 0; i < n; i++) {            //下标移到报数起始位置            if (s != 1) {                i = s - 1;                s = 1;            }            //该位置已被移除继续，到下个位置            if (array[i] == 0)                continue;            //报数增加            count++;            //符合要求，则打印、该位置抹0、个数自减            if (count == m) {                System.out.print(array[i]+(num==1?"":"-"));                array[i] = 0;                count = 0;                num--;            }        }    }}

参考：http://www.cnblogs.com/michael110/archive/2011/03/25/1995715.html

如有错误，欢迎纠正！