两个单链表生成相加链表

import java.util.Stack;//两个单链表生成相加链表public class plusList{    //链表节点的定义    public static class Node{      public int value;      public Node next;      public Node(int data)      {      this.value=data;      }    }    //(两个数计算求和)两个单链表相加生成的链表    public static Node pluslist(Node head1,Node head2)    {    if(head1==null)    {    return head2;    }else if(head2==null){             return head1;    }else if(head1==null&&head2==null)    {    return null;    }        int num1=0;        int num2=0;        int leng1=0;        int leng2=0;        Node p=head1;        while(p!=null)        {           ++leng1;           p=p.next;        }        Node q=head2;        while(q!=null)        {           ++leng2;           q=q.next;        }        while(head1!=null&&leng1>=0)        {        num1+=head1.value*Math.pow(10,leng1-1);        --leng1;        head1=head1.next;        }        while(head2!=null&&leng2>=0)        {        num2+=head2.value*Math.pow(10,leng2-1);        --leng2;        head2=head2.next;        }        int sum=num1+num2;   //两个数相加的和        System.out.println("计算的和为:"+sum);        String str=sum+" ";        char[]str2=str.toCharArray();        //head3=new Node(str2[0]);                for(int i=0;i<str2.length;i++)        {        System.out.println(str2[i]);        }        //记录新链表的头结点        Stack<Integer>stack=new Stack<Integer>();        while(sum!= 0){         int n = sum% 10;         //System.out.println(n);         stack.push(n);         sum /= 10;       }            Node head3=new Node(stack.pop());  //重新生成一个链表，保存两个数相加的和       Node res=head3;       while(!stack.isEmpty())       {           head3.next=new Node(stack.pop());           head3=head3.next;       }              return res;    }        //(利用双栈求解)两个单链表相加生成的链表    public static Node pluslist2(Node head1,Node head2)    {        if(head1==null)    {    return head2;    }else if(head2==null){             return head1;    }else if(head1==null&&head2==null)    {    return null;    }    Stack<Integer> s1 = new Stack<Integer>(); //保存链表1Stack<Integer> s2 = new Stack<Integer>(); //保存链表2while (head1 != null) {s1.push(head1.value);head1 = head1.next;}while (head2 != null) {s2.push(head2.value);head2 = head2.next;}int ca = 0;  //记录进位int n1 = 0;int n2 = 0;int n = 0;Node node = null;Node pre = null;while (!s1.isEmpty() || !s2.isEmpty()) {n1 = s1.isEmpty() ? 0 : s1.pop();n2 = s2.isEmpty() ? 0 : s2.pop();n = n1 + n2 + ca;pre = node;node = new Node(n % 10);node.next = pre;ca = n / 10;}if (ca == 1) {pre = node;node = new Node(1);node.next = pre;}return node;    }    //(利用链表的逆序求解)两个单链表相加生成的链表    public static Node pluslist3(Node head1,Node head2)    {     if(head1==null)    {    return head2;    }else if(head2==null){             return head1;    }else if(head1==null&&head2==null)    {    return null;    }head1 = reverseList(head1);head2 = reverseList(head2);int ca = 0;int n1 = 0;int n2 = 0;int n = 0;Node c1 = head1;Node c2 = head2;Node node = null;Node pre = null;while (c1 != null || c2 != null) {n1 = c1 != null ? c1.value : 0;n2 = c2 != null ? c2.value : 0;n = n1 + n2 + ca;pre = node;node = new Node(n % 10);node.next = pre;ca = n / 10;c1 = c1 != null ? c1.next : null;c2 = c2 != null ? c2.next : null;}if (ca == 1) {pre = node;node = new Node(1);node.next = pre;}reverseList(head1);reverseList(head2);return node;}    //逆序链表    public static Node reverseList(Node head) {Node pre = null;Node next = null;while (head != null) {next = head.next;head.next = pre;pre = head;head = next;}return pre;}    //打印链表    public static void PrintList(Node head)    {    while(head!=null)    {    System.out.print(head.value+" ");    head=head.next;    }    }public static void main(String[]args){//System.out.println("Hello 2017/11/3");Node node1=new Node(9);node1.next=new Node(3);node1.next.next=new Node(7);Node node2=new Node(6);node2.next=new Node(3);//node2.next.next=new Node(3);                //Node mode=pluslist(node1,node2);        //Node mode=pluslist2(node1,node2);        Node mode=pluslist3(node1,node2);        PrintList(mode);}}