Add Two Numbers

题意：
You are given two linked lists representing two non-negative numbers. The digits are stored in reverse
order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.
Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8
比如：
数字3 4 2 +
数字4 6 5 =
数字8 0 7

#include <stdlib.h>
#include <stdio.h>
typedef struct _LinkNode
{
    int data;
    struct _LinKNode *next;
}LinkNode;
typedef struct _Linklist
{
    LinkNode *head;
    int length;
}Linklist;
typedef struct _Student
{
    int id;
}Student;
//初始化
Linklist* Init()
{
    Linklist *list=(Linklist*)malloc(sizeof(Linklist));
    LinkNode *node=(LinkNode*)malloc(sizeof(LinkNode));
    list->length=0;
    list->head=node;
    node->next=NULL;
    return list;
}
//插入
void Push(Linklist* list,int pos,int data)
{
    //合法性检验
    if(list==NULL||pos<0)
        return;
    if(pos > list->length)
        pos=list->length;
    //创建辅助接点
    LinkNode *pCurrent=list->head;
    //创建新节点
    LinkNode *newnode=(LinkNode*)malloc(sizeof(LinkNode));
    newnode->data=data;
    //遍历找到插入节点的位置
    int i;
    for( i=0;i<pos;i++)
        pCurrent=pCurrent->next;
    //插入新节点
    newnode->next=pCurrent->next;
    pCurrent->next=newnode;
    list->length++;

}
void Print(Linklist *list)
{
    LinkNode *pCurrent;
    //合法性检验
    if(list==NULL)
        return;
    //创建辅助接点
    pCurrent=list->head->next;
    int i;
    //遍历打印
    for( i=0;i<list->length;i++)
    {
        printf("%2d",pCurrent->data);
        pCurrent=pCurrent->next;
    }
}
void Add(Linklist *s1,Linklist *s2,Linklist *s3)
{
    if(s1==NULL && s2==NULL)
    //创建辅助节点
    LinkNode *pCurrent1;
    pCurrent1=s1->head->next;
    LinkNode *pCurrent2;
    pCurrent2=s2->head->next;
    //c为进位，sum为两数相加的和，data为除去进位的数
    int c=0;
    int sum=0;
    int data=0;
    while(pCurrent1!=NULL&&pCurrent2!=NULL)
    {
        sum=pCurrent1->data+pCurrent2->data+c;
        c=sum/10;
        data=sum%10;
        Push(s3,s3->length,data);
        pCurrent1=pCurrent1->next;
        pCurrent2=pCurrent2->next;

    }
    //head->1->2->3->NULL   head->2->3->NULL
    while(pCurrent1!=NULL)
    {
        sum=pCurrent1->data+c;
        c=sum/10;
        data=sum%10;
        Push(s3,s3->length,data);
        pCurrent1=pCurrent1->next;

    }
    //head->1->2->NULL   head->1->2->3->NULL
    while(pCurrent2!=NULL)
    {
        sum=pCurrent2->data+c;
        c=sum/10;
        data=sum%10;
        Push(s3,s3->length,data);
        pCurrent2=pCurrent2->next;

    }
    //head->4->2->9->NULL   head->1->2->3->NULL
    if(c>0)
    {
       Push(s3,s3->length,c);
    }
}
int main()
{

    //创建链表初始化
    Linklist *list1=Init();
    Linklist *list2=Init();
    //插入数据
    Push(list1,0,3);
    Push(list1,0,4);
    Push(list1,0,2);

    Push(list2,0,4);
    Push(list2,0,6);
    Push(list2,0,9);
    Push(list2,0,7);
    Push(list2,0,5);
    //打印
    Print(list1);
    printf("\n");
    Print(list2);
    //两链表相加
    Linklist *list3=Init();
    Add(list1,list2,list3);
    //打印
    printf("\n");
    Print(list3);
    return 0;
}